javascript - Ajax simple example not working -

i haven't used ajax in while , can't simple program work, doing wrong ?

        <script type = "text/javascript" src = "jquery-1.9.1.min.js"></script>     <script type = "text/javascript">         alert("");         var count = 0;         $.ajax({                url: 'get.php',                datatype: 'json',                success: function ()                 {                        alert("");                }          });         alert("");     </script>  <?php echo "yay"; ?> 

thanks

setting datatype "json" means response get.php parsed json. if it's not valid json or response empty, request fail.

if url incorrect (can't found...http 404 error), request fail.

the default type of request "get", if get.php doesn't allow "get" (for reason), return http error, , request fail.

if there's error on server, return http 500 error, , request fail.

something debug add error option $.ajax call , see if that's called. instead, use .fail() method...it same thing.

of course, more direct way of debugging opening browser's console , viewing ajax request. should show multiple details it, can determine problems.

it might seem if ajax request never executed/sent, because don't see alert in middle. well, because request wasn't successful, doesn't mean skipped. there plenty of reasons (i named several above) why request may fail. , .fail() method determine cause.

also, universal convention handling deferred objects in jquery use done , fail methods, option. of course, $.ajax has specific options can specify (success, error, , complete - else), option. can use special methods (.success(), .error(), .complete()) part of object returned $.ajax, deprecated of version 1.8 - take @ .ajax docs towards bottom - http://api.jquery.com/jquery.ajax/ . here's how i'd set up, shouldn't different yours, catch errors:

$.ajax({     url: 'get.php',     datatype: 'json' }).done(data) {     console.log("successful response"); }).fail(jqxhr, textstatus, errorthrown) {     console.log("error: " + textstatus + ", " + errorthrown); });