更改提交按钮的值

It may take a long time to complete the call.php and get the return value, how can I change the submit button's value to "Processing … " while the call.php is being executed?

Submit button with id "submit_btn", there is no change to the script

$('#submit_btn').val('Processing …')

AJAX code

$(document).ready(function(){
    $('#form1').submit(function(e) {
        e.preventDefault();
        $('#submit_btn').val('Processing ...');
      $.ajax({
        cache: false, 
        type: "POST", 
        dataType: "json",
            data: $('#form1').serialize(),
        url: $('#form1').attr('action'),
        complete: function (HttpRequest, textStatus) {
                $('#submit_btn').val('Create');
      }});
      return false;
  });
});

HTML

<form action="call.php" method="POST" id="form1" name="form1">
        <input type="text" name="campname" id="campname">
        <textarea id="longdesc" name="longdesc"></textarea>
        <input type="text" name="vercode" id="vercode" />
        <input type="submit" value="Create" id="submit_btn" />
</form>

$(document).ready(function(){
    $('#submit_btn').click(function(e) {
        e.preventDefault();
        $(this).val('Processing ...'); // this did the trices 
      $.ajax({
        cache: false, 
        type: "POST", 
        dataType: "json",
            data: $('#form1').serialize(),
        url: $('#form1').attr('action'),
        complete: function (HttpRequest, textStatus) {
                $('#submit_btn').val('Create');
      }});
      return false;
  });
});

WORKING DEMO

For my this was the one that worked in a page with many forms with the same name and id

$(this).find("#submit").val("Saved");