function Validator(frmname) {
    this.formobj = document.forms[frmname];
    if (!this.formobj) {
        alert("BUG: couldnot get Form object " + frmname);
        return;
    }
    if (this.formobj.onsubmit) {
        this.formobj.old_onsubmit = this.formobj.onsubmit;
        this.formobj.onsubmit = null;
    }
    else {
        this.formobj.old_onsubmit = null;
    }
    this.formobj.onsubmit = form_submit_handler;
    this.addValidation = add_validation;
    this.setAddnlValidationFunction = set_addnl_vfunction;
    this.clearAllValidations = clear_all_validations;
}
function set_addnl_vfunction(functionname) {
    this.formobj.addnlvalidation = functionname;
}
function clear_all_validations() {
    for (var itr = 0; itr < this.formobj.elements.length; itr++) {
        this.formobj.elements[itr].validationset = null;
    }
}
function form_submit_handler() {
    for (var itr = 0; itr < this.elements.length; itr++) {
        if (this.elements[itr].validationset &&
	   !this.elements[itr].validationset.validate()) {
            return false;
        }
    }
    if (this.addnlvalidation) {
        str = " var ret = " + this.addnlvalidation + "()";
        eval(str);
        if (!ret) return ret;
    }
    return true;
}
function add_validation(itemname, descriptor, errstr) {
    if (!this.formobj) {
        alert("BUG: the form object is not set properly");
        return;
    } //if
    var itemobj = this.formobj[itemname];

    if (itemobj.length && isNaN(itemobj.selectedIndex))
    //for radio button; don't do for 'select' item
    {
        itemobj = itemobj[0];
    }
    if (!itemobj) {
        alert("BUG: Couldnot get the input object named: " + itemname);
        return;
    }

    if (!itemobj.validationset) {
        itemobj.validationset = new ValidationSet(itemobj);
    }
    itemobj.validationset.add(descriptor, errstr);
}
function ValidationDesc(inputitem, desc, error) {
    this.desc = desc;
    this.error = error;
    this.itemobj = inputitem;
    this.validate = vdesc_validate;
}
function vdesc_validate() {
    if (!validateInput(this.desc, this.itemobj, this.error)) {
        this.itemobj.focus();
        return false;
    }
    return true;
}
function ValidationSet(inputitem) {
    this.vSet = new Array();
    this.add = add_validationdesc;
    this.validate = vset_validate;
    this.itemobj = inputitem;
}
function add_validationdesc(desc, error) {
    this.vSet[this.vSet.length] =
  new ValidationDesc(this.itemobj, desc, error);
}
function vset_validate() {
    for (var itr = 0; itr < this.vSet.length; itr++) {
        if (!this.vSet[itr].validate()) {
            return false;
        }
    }
    return true;
}
/*  checks the validity of an email address entered 
*   returns true or false 
*/
function validateEmail(email) {
    var splitted = email.match("^(.+)@(.+)$");
    if (splitted == null) return false;
    if (splitted[1] != null) {
        var regexp_user = /^\"?[\w-_\.]*\"?$/;
        if (splitted[1].match(regexp_user) == null) return false;
    }
    if (splitted[2] != null) {
        var regexp_domain = /^[\w-\.]*\.[A-Za-z]{2,4}$/;
        if (splitted[2].match(regexp_domain) == null) {
            var regexp_ip = /^\[\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\]$/;
            if (splitted[2].match(regexp_ip) == null) return false;
        } // if
        return true;
    }
    return false;
}

function TestComparison(objValue, strCompareElement, strvalidator, strError) {
    var bRet = true;
    var objCompare = null;
    if (!objValue.form) {
        alert("BUG: No Form object!");
        return false
    }
    objCompare = objValue.form.elements[strCompareElement];
    if (!objCompare) {
        alert("BUG: Element with name" + strCompareElement + " not found !");
        return false;
    }
    if (strvalidator != "eqelmnt") {
        if (isNaN(objValue.value)) {
            alert(objValue.name + ": Should be a number ");
            return false;
        } //if 
        if (isNaN(objCompare.value)) {
            alert(objCompare.name + ": Should be a number ");
            return false;
        } //if 	  
    } //if
    var cmpstr = "";
    switch (strvalidator) {
        case "eqelmnt":
            {
                if (objValue.value != objCompare.value) {
                    cmpstr = " should be equal to ";
                    bRet = false;
                } //if
                break;
            } //case
        case "ltelmnt":
            {
                if (eval(objValue.value) >= eval(objCompare.value)) {
                    cmpstr = " should be less than ";
                    bRet = false;
                }
                break;
            } //case
        case "leelmnt":
            {
                if (eval(objValue.value) > eval(objCompare.value)) {
                    cmpstr = " should be less than or equal to";
                    bRet = false;
                }
                break;
            } //case		
        case "gtelmnt":
            {
                if (eval(objValue.value) <= eval(objCompare.value)) {
                    cmpstr = " should be greater than";
                    bRet = false;
                }
                break;
            } //case
        case "geelmnt":
            {
                if (eval(objValue.value) < eval(objCompare.value)) {
                    cmpstr = " should be greater than or equal to";
                    bRet = false;
                }
                break;
            } //case
    } //switch
    if (bRet == false) {
        if (!strError || strError.length == 0) {
            strError = objValue.name + cmpstr + objCompare.value;
        } //if
        alert(strError);
    } //if
    return bRet;
}
function TestSelMin(objValue, strMinSel, strError) {
    var bret = true;
    var objcheck = objValue.form.elements[objValue.name];
    var chkcount = 0;
    if (objcheck.length) {
        for (var c = 0; c < objcheck.length; c++) {
            if (objcheck[c].checked == "1") {
                chkcount++;
            } //if
        } //for
    }
    else {
        chkcount = (objcheck.checked == "1") ? 1 : 0;
    }
    var minsel = eval(strMinSel);
    if (chkcount < minsel) {
        if (!strError || strError.length == 0) {
            strError = "Please Select atleast" + minsel + " check boxes for" + objValue.name;
        } //if                                                               
        alert(strError);
        bret = false;
    }
    return bret;
}

function TestDontSelectChk(objValue, chkValue, strError) {
    var pass = true;
    var objcheck = objValue.form.elements[objValue.name];
    if (objcheck.length) {
        var idxchk = -1;
        for (var c = 0; c < objcheck.length; c++) {
            if (objcheck[c].value == chkValue) {
                idxchk = c;
                break;
            } //if
        } //for
        if (idxchk >= 0) {
            if (objcheck[idxchk].checked == "1") {
                pass = false;
            }
        } //if
    }
    else {
        if (objValue.checked == "1") {
            pass = false;
        } //if
    } //else
    if (pass == false) {
        if (!strError || strError.length == 0) {
            strError = "Can't Proceed as you selected " + objValue.name;
        } //if			  
        alert(strError);

    }
    return pass;
}

function TestRequiredInput(objValue, strError) {
    var ret = true;
    if (eval(objValue.value.length) == 0) {
        if (!strError || strError.length == 0) {
            strError = objValue.name + " : Required Field";
        } //if 
        alert(strError);
        ret = false;
    } //if 
    return ret;
}

function TestMaxLen(objValue, strMaxLen, strError) {
    var ret = true;
    if (eval(objValue.value.length) > eval(strMaxLen)) {
        if (!strError || strError.length == 0) {
            strError = objValue.name + " : " + strMaxLen + " characters maximum ";
        } //if 
        alert(strError + "\n[Current length = " + objValue.value.length + " ]");
        ret = false;
    } //if 
    return ret;
}

function TestMinLen(objValue, strMinLen, strError) {
    var ret = true;
    if (eval(objValue.value.length) < eval(strMinLen)) {
        if (!strError || strError.length == 0) {
            strError = objValue.name + " : " + strMinLen + " characters minimum  ";
        } //if               
        alert(strError + "\n[Current length = " + objValue.value.length + " ]");
        ret = false;
    } //if 
    return ret;
}

function TestInputType(objValue, strRegExp, strError, strDefaultError) {
    var ret = true;

    var charpos = objValue.value.search(strRegExp);
    if (objValue.value.length > 0 && charpos >= 0) {
        if (!strError || strError.length == 0) {
            strError = strDefaultError;
        } //if 
        alert(strError + "\n [Error character position " + eval(charpos + 1) + "]");
        ret = false;
    } //if 
    return ret;
}

function TestEmail(objValue, strError) {
    var ret = true;
    if (!validateEmail(objValue.value)) {
        if (!strError || strError.length == 0) {
            strError = objValue.name + ": Enter a valid Email address ";
        } //if                                               
        alert(strError);
        ret = false;
    } //if 
    return ret;
}

function TestLessThan(objValue, strLessThan, strError) {
    var ret = true;
    if (isNaN(objValue.value)) {
        alert(objValue.name + ": Should be a number ");
        ret = false;
    } //if 
    else
        if (eval(objValue.value) >= eval(strLessThan)) {
        if (!strError || strError.length == 0) {
            strError = objValue.name + " : value should be less than " + strLessThan;
        } //if               
        alert(strError);
        ret = false;
    } //if   
    return ret;
}

function TestGreaterThan(objValue, strGreaterThan, strError) {
    var ret = true;
    if (isNaN(objValue.value)) {
        alert(objValue.name + ": Should be a number ");
        ret = false;
    } //if 
    else
        if (eval(objValue.value) <= eval(strGreaterThan)) {
        if (!strError || strError.length == 0) {
            strError = objValue.name + " : value should be greater than " + strGreaterThan;
        } //if               
        alert(strError);
        ret = false;
    } //if  
    return ret;
}

function TestRegExp(objValue, strRegExp, strError) {
    var ret = true;
    if (!objValue.value.match(strRegExp)) {
        if (!strError || strError.length == 0) {
            strError = objValue.name + ": Invalid characters found ";
        } //if                                                               
        alert(strError);
        ret = false;
    } //if 
    return ret;
}
function TestDontSelect(objValue, index, strError) {
    var ret = true;
    if (objValue.selectedIndex == null) {
        alert("BUG: dontselect command for non-select Item");
        ret = false;
    }
    else
        if (objValue.selectedIndex == eval(index)) {
        if (!strError || strError.length == 0) {
            strError = objValue.name + ": Please Select one option ";
        } //if                                                               
        alert(strError);
        ret = false;
    }
    return ret;
}

function TestSelectOneRadio(objValue, strError) {
    var objradio = objValue.form.elements[objValue.name];
    var one_selected = false;
    for (var r = 0; r < objradio.length; r++) {
        if (objradio[r].checked == "1") {
            one_selected = true;
            break;
        }
    }
    if (false == one_selected) {
        if (!strError || strError.length == 0) {
            strError = "Please select one option from " + objValue.name;
        }
        alert(strError);
    }
    return one_selected;
}

//*  Checks each field in a form 
function validateInput(strValidateStr, objValue, strError) {
    var ret = true;
    var epos = strValidateStr.search("=");
    var command = "";
    var cmdvalue = "";
    if (epos >= 0) {
        command = strValidateStr.substring(0, epos);
        cmdvalue = strValidateStr.substr(epos + 1);
    }
    else {
        command = strValidateStr;
    }

    switch (command) {
        case "req":
        case "required":
            {
                ret = TestRequiredInput(objValue, strError)
                break;
            }
        case "maxlength":
        case "maxlen":
            {
                ret = TestMaxLen(objValue, cmdvalue, strError)
                break;
            }
        case "minlength":
        case "minlen":
            {
                ret = TestMinLen(objValue, cmdvalue, strError)
                break;
            }
        case "alnum":
        case "alphanumeric":
            {
                ret = TestInputType(objValue, "[^A-Za-z0-9]", strError,
						objValue.name + ": Only alpha-numeric characters allowed ");
                break;
            }
        case "alnum_s":
        case "alphanumeric_space":
            {
                ret = TestInputType(objValue, "[^A-Za-z0-9\\s]", strError,
						objValue.name + ": Only alpha-numeric characters and space allowed ");
                break;
            }
        case "num":
        case "numeric":
            {
                ret = TestInputType(objValue, "[^0-9]", strError,
						objValue.name + ": Only digits allowed ");
                break;
            }
        case "alphabetic":
        case "alpha":
            {
                ret = TestInputType(objValue, "[^A-Za-z]", strError,
						objValue.name + ": Only alphabetic characters allowed ");
                break;
            }
        case "alphabetic_space":
        case "alpha_s":
            {
                ret = TestInputType(objValue, "[^A-Za-z\\s]", strError,
						objValue.name + ": Only alphabetic characters and space allowed ");
                break;
            }
        case "email":
            {
                ret = TestEmail(objValue, strError);
                break;
            }
        case "lt":
        case "lessthan":
            {
                ret = TestLessThan(objValue, cmdvalue, strError);
                break;
            }
        case "gt":
        case "greaterthan":
            {
                ret = TestGreaterThan(objValue, cmdvalue, strError);
                break;
            }
        case "regexp":
            {
                ret = TestRegExp(objValue, cmdvalue, strError);
                break;
            }
        case "dontselect":
            {
                ret = TestDontSelect(objValue, cmdvalue, strError)
                break;
            }
        case "dontselectchk":
            {
                ret = TestDontSelectChk(objValue, cmdvalue, strError)
                break;
            }
        case "selmin":
            {
                ret = TestSelMin(objValue, cmdvalue, strError);
                break;
            }
        case "selone":
            {
                ret = TestSelectOneRadio(objValue, strError);
                break;
            }
            //Comparisons
        case "eqelmnt":
        case "ltelmnt":
        case "leelmnt":
        case "gtelmnt":
        case "geelmnt":
            {
                return TestComparison(objValue, cmdvalue, command, strError);
                break;
            }
    } //switch 
    return ret;
}