javascript - form.submit() not working in the below code -

the javascript not submit form. on clicking alert called, checked object , not null. .submit() method not submit form. stuck here long time.

<script type="text/javascript">  $(document).ready(function(){         $("label img").click(function(){              alert("11");             $("#" + $(this).parents("label").attr("for")).click();                });         $("input").change(uploadform);  }); </script> <script type="text/javascript"> function uploadform(){     alert("1");     document.getelementbyid('uploadfileformid').submit(); } </script>  <form id="uploadfileformid" action="uploadfile" method="post"                 enctype="multipart/form-data"                  style="width: 40px">                  <label for="uploadfileid">                  <img src="images/button_up_lo.png"                onmouseover="this.src='images/button_up_hi.png'"                onmouseout="this.src='images/button_up_lo.png'" />                  </label>                 <span id="uploadspanid" class="hidden">                   <input type="file"                   name="uploadfilename"                  id="uploadfileid"/>                  <button type= "submit" id="uploadbuttonid" name= "uploadbutton" ></button>                    </span>            </form> 

1. try <input type="submit">
2. use $('#uploadbuttonid').submit(); since using jquery.
3. element id case sensitive (uploadbuttonid vs uploadfileformid)