Mine

<script>
   function showload(b)
   {
      var loadi = 0;
      b.disabled = true;
      b.value = 'Loading';
      loadi+=1;
      if (loadi>3)loadi=0;
      b.value = "Loading"
      for (var i=0;i<loadi;i++) b.value+='.'
      setTimeout(showload,100);
   }
</script>

<input type="submit" style="width:100px; height:21px;" name="SubmitButton" id="SubmitButton" value="Submit" onclick="showload(this);">