XMLHttpRequest - Post Method

function getNewHTTPObject()
{
var xmlhttp;
if (!xmlhttp && typeof XMLHttpRequest != 'undefined')
{
try
{
xmlhttp = new XMLHttpRequest();
}
catch (e)
{
xmlhttp = false;
}
}
return xmlhttp;
}
/*this function post successfully*/
function postForm(getposturl)
{
var xmlvalue=null;
var xmlpost = new getNewHTTPObject();
xmlpost.onreadystatechange=Gtpost;
xmlvalue="posttitle="+ posttitle.value +"&txtnewpost="+post1.value;
var tmppost = encodeURI(getposturl);
xmlpost.open('POST', tmppost, false);
xmlpost.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlpost.setRequestHeader("Content-length", xmlvalue.length);
xmlpost.setRequestHeader("Connection", "close");
xmlpost.send(xmlvalue);
return;
}