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) {
        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 (!V2validateData(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;
}

function validateEmailv2(email) {
    // a very simple email validation checking. 
    // you can add more complex email checking if it helps 
    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 V2validateData(strValidateStr, objValue, strError) {
    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":
        {
            if (eval(objValue.value.length) == 0) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + " : Required Field";
                }
                //if 
                alert(strError);
                return false;
            }
            //if 
            break;
        }
        //case required 
        case "maxlength":
    case "maxlen":
        {
            if (eval(objValue.value.length) > eval(cmdvalue)) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + " : " + cmdvalue + " characters maximum ";
                }
                //if 
                alert(strError + "\n[Current length = " + objValue.value.length + " ]");
                return false;
            }
            //if 
            break;
        }
        //case maxlen 
        case "minlength":
    case "minlen":
        {
            if (eval(objValue.value.length) < eval(cmdvalue)) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + " : " + cmdvalue + " characters minimum  ";
                }
                //if               
                alert(strError + "\n[Current length = " + objValue.value.length + " ]");
                return false;
            }
            //if 
            break;
        }
        //case minlen 
        case "alnum":
    case "alphanumeric":
        {
            var charpos = objValue.value.search("[^A-Za-z0-9]");
            if (objValue.value.length > 0 && charpos >= 0) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + ": Only alpha-numeric characters allowed ";
                }
                //if 
                alert(strError + "\n [Error character position " + eval(charpos + 1) + "]");
                return false;
            }
            //if 
            break;
        }
        //case alphanumeric 
        case "num":
    case "numeric":
        {
            var charpos = objValue.value.search("[^0-9]");
            if (objValue.value.length > 0 && charpos >= 0) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + ": Only digits allowed ";
                }
                //if               
                alert(strError + "\n [Error character position " + eval(charpos + 1) + "]");
                return false;
            }
            //if 
            break;
        }
        //numeric 
        case "alphabetic":
    case "alpha":
        {
            var charpos = objValue.value.search("[^A-Za-z]");
            if (objValue.value.length > 0 && charpos >= 0) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + ": Only alphabetic characters allowed ";
                }
                //if                             
                alert(strError + "\n [Error character position " + eval(charpos + 1) + "]");
                return false;
            }
            //if 
            break;
        }
        //alpha 
        case "alnumhyphen":
        {
            var charpos = objValue.value.search("[^A-Za-z0-9\-_]");
            if (objValue.value.length > 0 && charpos >= 0) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + ": characters allowed are A-Z,a-z,0-9,- and _";
                }
                //if                             
                alert(strError + "\n [Error character position " + eval(charpos + 1) + "]");
                return false;
            }
            //if 			
            break;
        }
    case "email":
        {
            if (!validateEmailv2(objValue.value)) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + ": Enter a valid Email address ";
                }
                //if                                               
                alert(strError);
                return false;
            }
            //if 
            break;
        }
        //case email 
        case "lt":
    case "lessthan":
        {
            if (isNaN(objValue.value)) {
                alert(objValue.name + ": Should be a number ");
                return false;
            }
            //if 
            if (eval(objValue.value) >= eval(cmdvalue)) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + " : value should be less than " + cmdvalue;
                }
                //if               
                alert(strError);
                return false;
            }
            //if             
            break;
        }
        //case lessthan 
        case "gt":
    case "greaterthan":
        {
            if (isNaN(objValue.value)) {
                alert(objValue.name + ": Should be a number ");
                return false;
            }
            //if 
            if (eval(objValue.value) <= eval(cmdvalue)) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + " : value should be greater than " + cmdvalue;
                }
                //if               
                alert(strError);
                return false;
            }
            //if             
            break;
        }
        //case greaterthan 
        case "regexp":
        {
            if (!objValue.value.match(cmdvalue)) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + ": Invalid characters found ";
                }
                //if                                                               
                alert(strError);
                return false;
            }
            //if 
            break;
        }
        //case regexp 
        case "dontselect":
        {
            if (objValue.selectedIndex == null) {
                alert("BUG: dontselect command for non-select Item");
                return false;
            }
            if (objValue.selectedIndex == eval(cmdvalue)) {
                if (!strError || strError.length == 0) {
                    strError = objValue.name + ": Please Select one option ";
                }
                //if                                                               
                alert(strError);
                return false;
            }
            break;
        }
        //case dontselect 
        }
    //switch 
    return true;
}