Changer le bouton browse d'un input type=file

<FORM name="myform" action="page.html" method="get" enctype="multipart/form-data">
  <SPAN stype="position:relative;z-index:0;">
    <INPUT type="text" size=12 name="myFileText">
    <INPUT type="image" src="browse.gif" border="0">
    <INPUT type="image" name="submit" value="fileValue" src="submit.gif">
    <SPAN STYLE="position:absolute;middle:0px;left:0px;z-index:1;">
      <INPUT type="hidden" name="fileOp" value="fileValue">
      <SCRIPT type="text/javascript">
        function fillForm() { document.myform.myFileText.value=document.myform.upName.value; }
      </SCRIPT>
      <INPUT type="file" style="-moz-opacity:0;filter:alpha(opacity:0);-khtml-opacity:0;"
        size=1 name="upName" onkeyup="fillForm();" onmouseout="fillForm();">
    </SPAN>
  </SPAN>
</FORM>

<input type="file" id="monInputFile" style="visibility:hidden"/>

<input type="button" style="border:1px solid #000;width:100px;height:30px;background-color:#CCC;" onclick="$('#monInputFile').click();"/>