ขอคำแนะนำเกียวกับ เรื่อง javascript หน่อยคับโดยใช้ DropDownList แล้วแสดง บน text field

<script type="text/javascript"> 
function putData(_objindex) { 
	if (_objindex != 0) {
		var x=0;
	   var _cdate = document.getElementById("hcdate").value.split(",");
	   var _ctime = document.getElementById("hsttime").value.split(",");
      
	   document.form1.c_date.value = _cdate[_objindex];
	   document.form1.st_time.value = _ctime[_objindex];
		
		
	}
	else {
	document.form1.c_date.value = "";
	document.form1.st_time.value = "";	
	}
}
</SCRIPT>

<form id="form1" name="form1" method="post" action="">

<?php
$hcdate = "";
$hsttime = "";
?>
  <select name="c_id1" id="c_id1"onchange="putData(this.selectedIndex)" >
    <option value=0>-----เลือก-----</option>
    <?
					include "DB.php";
						$sql="select * from compare ";
						$resultM2=mysql_query($sql);
					while($record=mysql_fetch_array($resultM2)){

					 $hcdate .= ",".$record[2];
                                         $hsttime .= ",". $record[3];
					  
					?>
    <option value="<?=$record[1];?>">
      <?=$record["1"]?>
    </option>
    <?	
					}
			
				?>
  </select>		
  


 <input name="c_date" type="text" disabled id="c_date">
<input name="st_time" type="text" disabled id="st_time">
<input  type="hidden" name="hcdate" id="hcdate" value="<?=$hcdate?>">
<input  type="hidden" name="hsttime" id="hsttime" value="<?=$hsttime?>">
  
  	
  
</form>