Hi,

I have a text field and when user enters few characters in this textfield ,it creates an Ajax request and searches the data from db and populate a dropdown which is next field .

This functionality is working fine but currently observed an issue that if user keeps entering the characters and back space in text field(say 15-20 times)

eg: User enters 'a' and then back space and then enter 'ab' and then backspace and enter 'abc' and so on .

For first 15 requests Ajax call is working fine and data is populating properly however between 15-20 request some where it hangs and I debugged the code and found that all of a sudden request.responseXML becomes null which caused the page to hangs.

Does any one know why after 15 request all of a sudden request.responseXML becomes null . Is there any limitations of number of response in AJAX.

Below is sample code which i am using .

var http = getXMLHTTPRequest();

var modurl = "/url + encodeURI(textEntered);  

http.open("GET", modurl, true);

http.onreadystatechange =         function() { 

 try{

 if (http.readyState == 4) {

if(http.status == 200) {

var res=  http.responseXML;

if (res != null) {

// Some Code here

}

}                                                                                                                                    

http.send(null);                                                                                                                               }

Thanks in advance for your response.