// JavaScript Document	  
<!-- javascript Check Email Address Field -->
// 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 = 9;

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 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){
s=stripCharsInBag(strPhone,validWorldPhoneChars);
return (isInteger(s) && s.length >= minDigitsInIPhoneNumber);
}

<!-------------End Phone---------->
<!-- check Email -->
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(){

	// Telephone
	var Phone=document.TheForm.tel
	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
	}
	// Email
	var emailID=document.TheForm.email
	if((emailID.value==null)||(emailID.value=="")){
	alert("Please Enter Your E-mail ID")
	emailID.focus()
	return false
	}
	// E-mail Comfirmation
	var emailReID=document.TheForm.retype_email
	if(emailID.value!=emailReID.value){
	alert("Please Enter Your Valid E-mail Confirmation !")
	emailReID.value=""
	emailReID.focus()
	return false
	}
	if(echeck(emailID.value)==false){
	emailID.value=""
	emailID.focus()
	return false
	}
	// Name
	var nm = document.TheForm.name
	if(nm.value==""){
	alert("Please Enter Your Full Name!")
	nm.focus()
	return false
	}
	// Address
	var ad = document.TheForm.address
	if(ad.value==""){
	alert("Please Enter Your Address!")
	ad.focus()
	return false
	}
	// Country
	var ctr=document.TheForm.country
	if(ctr.value==""){
		alert("Please Enter Your Country!")
		ctr.focus();
		return false
	}
	// Message
	var msg = document.TheForm.msg
	if(msg.value==""){
	alert("Please Enter Your Comments!")
	msg.focus()
	return false
	}
<!------------------------>
	return true
 }