function GetXmlHttpObject(){
     var objXMLHttp=null;
     if(window.XMLHttpRequest){
          objXMLHttp = new XMLHttpRequest();
     }
     else if (window.ActiveXObject){
          objXMLHttp = new ActiveXObject("Microsoft.XMLHttp");
     }
     return objXMLHttp;
}

function newsletter()
  {  
	var xmlHttp;
	xmlHttp = GetXmlHttpObject();  
	if (xmlHttp==null)  
	{  
		alert ('Your browser does not support AJAX!');  
		return;  
	} 
  xmlHttp.onreadystatechange=function()
  {
  if(xmlHttp.readyState==4)
   {
		document.getElementById("newsletter").innerHTML = xmlHttp.responseText;

    }
 }
    xmlHttp.open("GET","newsletter.aspx",true);
    xmlHttp.send(null);  
}