// JavaScript Document                  
<!--
// Declaring required variables
var digits = "0123456789";
// non-digit characters which are allowed in phone numbers
var phoneNumberDelimiters = "()-. ";
// characters which are allowed in international phone numbers
// (a leading + is OK)
var validWorldphoneChars = phoneNumberDelimiters + "+";
// Minimum no of digits in an international phone no.
var minDigitsInIphoneNumber = 10;

function isInteger(s)
{   var i;
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}
function trim(s)
{   var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not a whitespace, append to returnString.
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (c != " ") returnString += c;
    }
    return returnString;
}
function stripCharsInBag(s, bag)
{   var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function checkInternationalphone(strphone){
var bracket=3
strphone=trim(strphone)
if(strphone.indexOf("+")>1) return false
if(strphone.indexOf("-")!=-1)bracket=bracket+1
if(strphone.indexOf("(")!=-1 && strphone.indexOf("(")>bracket)return false
var brchr=strphone.indexOf("(")
if(strphone.indexOf("(")!=-1 && strphone.charAt(brchr+2)!=")")return false
if(strphone.indexOf("(")==-1 && strphone.indexOf(")")!=-1)return false
s=stripCharsInBag(strphone,validWorldphoneChars);
return (isInteger(s) && s.length >= minDigitsInIphoneNumber);
}

function echeck(str) {

		var at="@"
		var dot="."
		var lat=str.indexOf(at)
		var lstr=str.length
		var ldot=str.indexOf(dot)
		if (str.indexOf(at)==-1){
		   alert("Invalid E-mail ID")
		   return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("Invalid E-mail ID")
		   return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("Invalid E-mail ID")
		    return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("Invalid E-mail ID")
		    return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("Invalid E-mail ID")
		    return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("Invalid E-mail ID")
		    return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    alert("Invalid E-mail ID")
		    return false
		 }

 		 return true					
	}
function ValidateForm(){
	var name=document.form1.name
	var email1=document.form1.email1
	var phone=document.form1.txtphone
	
	if((name.value==null)||(name.value==""))
	{
		alert("Please enter your name")
		name.focus()
		return false
	}
	if ((email1.value==null)||(email1.value=="")){
		alert("Please enter a valid email address")
		email1.focus()
		return false
	}
	if (echeck(email1.value)==false){
		email1.value=""
		email1.focus()
		return false
	}
	if((phone.value==null)||(phone.value==""))
	{
		alert("Please provide a phone number")
		phone.focus()
		return false
	}
	if ((phone.value==null)||(phone.value=="")){
		alert("Please enter your phone number")
		phone.focus()
		return false
	}
	if (checkInternationalphone(phone.value)==false){
		alert("Please enter a valid phone number")
		phone.value=""
		phone.focus()
		return false
	}
	return true
 }
//-->