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();


function sndReq(action,url) {
    http.open('post', url, true);
    http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    http.setRequestHeader("Content-length", action.length);
    http.setRequestHeader("Connection", "close");
    http.onreadystatechange = handleResponse;
    http.send(action);
}


function handleResponse() {

     if(http.readyState == 4){
          var response = http.responseText;
	  document.getElementById('mainContent').innerHTML = response;
     }
}