function createRequestObject() {
    var ro;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        ro = new ActiveXObject("Microsoft.XMLHTTP");
    }else{
        ro = new XMLHttpRequest();
    }
    return ro;
}

var http = createRequestObject();




     var c=0
     var t
     function timedCount()
     {
          

          t=setTimeout("timedCount()",30000)
          call();
     }
     function call()
     {

    http.open('get', 'display.php');
    http.onreadystatechange = handleResponse;
    http.send(null);
    
     }

function handleResponse() {
    if(http.readyState == 4){
        var response = http.responseText;        
        var update = new Array();        
          ob = document.getElementById('refresh_content');
          ob.innerHTML = response;            
        
    }
}