I have set UpdateProxy for a ext.net store and calling it's save method from javascript code.

it is working perfectly fine but I need to perform some task after completion of "SAVE" functionality. Therefore, I have used a callback function. I am also using this callback function in "store.load", which is working fine. but in "store.save" callback is not working properly. When I say "Properly" it means this callback function is executing only once and not second or third time until I refresh the complete page and rerun save command. I have also tried
success:
but success is not working completely.

#{dsLetterUserTag}.save(
 {
    callback: function(result){
         alert('i am here' + result);

    }
                          
});
The proxy setting is as under:
<UpdateProxy>
  <ext:HttpWriteProxy Url="~/Hrs/SaveOrUpdateRecord/" />
</UpdateProxy>