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 email address. Please double-check.")
		   return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("Invalid email address. Please double-check.")
		   return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("Invalid email address. Please double-check.")
		    return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("Invalid email address. Please double-check.")
		    return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("Invalid email address. Please double-check.")
		    return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("Invalid email address. Please double-check.")
		    return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    alert("Invalid email address. Please double-check.")
		    return false
		 }

 		 return true					
	}
	
// 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 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);
}
	



function validateform() {
	
	
	if (document.catalog_request.firstname.value == '') 
	{
		alert('First Name is a required field. Please fill it in.');
		document.catalog_request.firstname.focus();
		return false;
	}
	
	if (document.catalog_request.lastname.value == '') 
	{
		alert('Last Name is a required field. Please fill it in.');
		document.catalog_request.lastname.focus();
		return false;
	}
	
	if (document.catalog_request.email.value == '') 
	{
		alert('Email is a required field. Please fill it in.');
		document.catalog_request.email.focus();
		return false;
	}
	
	if (echeck(document.catalog_request.email.value)==false)
	{
		document.catalog_request.email.focus();
		return false;
	}
	if (document.catalog_request.phone_no.value == '') 
	{
		alert('Phone is a required field. Please fill it in.');
		document.catalog_request.phone_no.focus();
		return false;
	}
	if (checkInternationalPhone(document.catalog_request.phone_no.value)==false)
	{
		alert('Please Enter a Valid Phone Number');
		document.catalog_request.phone_no.value= "";
		document.catalog_request.phone_no.focus();
		return false;
	}
	
	if (document.catalog_request.address.value == '') 
	{
		alert('Address is a required field. Please fill it in.');
		document.catalog_request.address.focus();
		return false;
	}
	if (document.catalog_request.city.value == '') 
	{
		alert('City is a required field. Please fill it in.');
		document.catalog_request.city.focus();
		return false;
	}
	if (document.catalog_request.state.value == '') 
	{
		alert('State is a required field. Please fill it in.');
		document.catalog_request.state.focus();
		return false;
	}
	if (document.catalog_request.zipcode.value == '') 
	{
		alert('Zip Code is a required field. Please fill it in.');
		document.catalog_request.zipcode.focus();
		return false;
	}
		
	
	return true;
}