function CreateHTTPRequest()
{
	var xmlHttp;
	try
	{
		xmlHttp=new XMLHttpRequest();
	}
	catch (e)
	{
		try
		{
			xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e)
		{
			try
			{
				xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
			}
			catch (e)
			{
				alert("Your browser does not support AJAX!");
				return false;
			}
		}
	}
	
	return xmlHttp;
}

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 SubmitNewsletter()
{
	document.getElementById("loading_area").style.visibility = "visible";
	
	var xmlHttp = CreateHTTPRequest();
	xmlHttp.onreadystatechange=function()
	{
		if(xmlHttp.readyState==4)
		{
			var response_str = xmlHttp.responseText;
			
			if(xmlHttp.status == 200)
			{
				document.getElementById("loading_area").style.visibility = "hidden";
				document.getElementById("email").value = "Enter your email address here";
				//alert("done");
				if(response_str == '1')
				{
					alert("You have been subscribed to our newsletter.");
				}
			}
			else if(xmlHttp.status == 500)
			{
				alert("server side script error");
			}
		}
	}
	
	email_address = document.getElementById("email").value;
	
	if(echeck(email_address))
	{
	
		var parameters = 'email_address=' + email_address;
		
		xmlHttp.open('POST', '/subscribe.php', true);
		xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
		xmlHttp.setRequestHeader("Content-length", parameters.length);
		xmlHttp.setRequestHeader("Connection", "close");
		xmlHttp.send(parameters);
	}
	else
	{
		alert("Please enter valid email address!");
	}
}