Hello @kartik,
It is always best practice to do something like this.
var $request;
if ($request != null){ 
    $request.abort();
    $request = null;
}
$request = $.ajax({
    type : "POST", //TODO: Must be changed to POST
    url : "yourfile.php",
    data : "data"
    }).done(function(msg) {
        alert(msg);
    });
But it is much better if you check an if statement to check whether the ajax request is null or not.
Hope it is helpful!!
Thank You!