var xmlHttp

function setloading(){
 document.getElementById("displaybox").innerHTML = '<table border=0 style="height:500px;"><tr><td><img src="../images/loading.gif" alt="Loading ..."><br>Please wait while loading...</td></tr></table>';
}

function returntomain(){
setloading();
getPage('main');
}

function getPage(Page){
xmlHttp=GetXmlHttpObject()
if (xmlHttp==null){
 alert ("Browser does not support HTTP Request")
 return
 } 
var url="index.php"
url=url+"?p="+Page
xmlHttp.onreadystatechange=stateChanged 
xmlHttp.open("GET",url,true)
xmlHttp.send(null)
} 

function stateChanged(){
 if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete"){ 
 document.getElementById("displaybox").innerHTML=xmlHttp.responseText;
 } 
} 

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