Jquery autocomplete not working when I use this two times in one page

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jQuery

jQuery-UI

Hi when i use jquery autocomplete in a page its working well.Now i have a page which have two field.one is for searching subject and another is for searching institute.When i use jquery autocomplete in both fields it can not work.only first field work second field can not work.My code is given below:

<script type="text/javascript">
$("#"+fieldID+"").autocomplete({
	source: function(request, response) {
            $.ajax({
                url: "autocomp3.asp",
                dataType: "json",
                data: {
                    term : request.term
                },
                success: function(data) {
					
                    response(data);
                }
            });
        },
        minLength: 3,
        delay: 300,
		select: function (event, ui) {
				//$("#txtAllowSearch").val(ui.item.label); // display the selected text
				$("#"+hiddenIdField+"").val(ui.item.id); // save selected id to hidden input
    	}
    });
</script>


<script type="text/javascript">
  
  var fieldID ="";
  
   
   function SetParam(fID)
   {
	  fieldID       = fID;
	  
   }
  
</script>


<input type="text" id="subject"   >
<input type="text" id="institute" >

plz help me how to solve this problem

What I have tried:

i use this
<input type="text" id="subject" >
<input type="text" id="institute" >

onclick() to set the id dynamic