定期进行AJAX

I'm calling ajax at regular interval (10 sec) from javascript to load data from the db. The response is listed in a small div. But once every 10 sec, I face the problem of interface not responding to user actions like mouse click, key press etc. Any help on this topic would be appreciated.

Code

var onlineLeads = function () {
var reqst ="";
var size="";
var url ="<s:property value="str_applicationPath"/>/Marketing/Online_showNewRequest";   
xmlHttp.open("POST", url, false);                                           
xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");  
xmlHttp.setRequestHeader("Connection", "close");
xmlHttp.onreadystatechange = function() {//Call a function when the state changes.
if(xmlHttp.readyState == 4 && xmlHttp.status == 200) {

//Code for display

}
}
xmlHttp.send(); 
setTimeout(onlineLeads, 15000);
};
setTimeout(onlineLeads, 1000);

You aren't performing Ajax:

xmlHttp.open("POST", url, false); 
//                        ^^^^^ 
//        Puts the request into synchronous mode

In synchronous mode, the call blocks until the response comes back. This ties up the JS event loop.

Change false to true.