Ajax Issues

programming web dev
1

Hello,
I am having a problem where my ajax dissapears randomly. I am assuming that it makes a call and gets nothing back so it delivers nada. Can anyone help? Is there a way to say “if you get nothing, do nothing?”
The file get_response.php it calls simple returns a value from mysql.

<script> 
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() { 
    http.open('get', 'get_response.php'); 
    http.onreadystatechange = handleResponse; 
    http.send(null); 
    setTimeout("sndReq()", 2000); // Recursive JavaScript function calls sndReq() every 2 seconds 
} 
function handleResponse() { 
    if(http.readyState == 4){ 
        var response = http.responseText; 
        if (response != responseold || responsecheck != 1) { 
            var responsecheck = 1; 
            document.getElementById("messagesb").innerHTML = http.responseText; 
            var responseold = response; 
        } 
    } 
} 
 
</script>