การใช่งาน OnChange="bind(this.value)" ครับบบงงมากเลย

<select name="name" id="name" OnChange="bind(this)" >
   <option value="1">1</option>
   <option value="2">2</option>
   <option value="3">3</option>
</select>

<input name="customer" id="customer" type="text"  id="customer"/>

<script language="javascript">
function bind(objSelect){
	  document.getElementById("customer").value = objSelect.options[objSelect.selectedIndex].value;
}
</script>

<input name="customer" type="text" class="SizeRed" id="customer" size="20"/>รายชื่อลูกค้า
              <select name="fname" id="fname" OnChange="bind(this.value)" >  
						 <option  value="0" id="s0<?= $fname ?>" >Select</option> 
			<?php  
                            $q="select fname from rs_custom ";  
                            $qr=mysql_query($q);  
                            while($rs=mysql_fetch_array($qr)){  
                        ?>  
                          <option value="<?=$rs['id']?>"><?=$rs['fname']?></option>  
                        <?php } ?>      
              </select>


<script language="javascript">
function bind(){
	document.form1.customer.value = document.form1.fname.selected;
}
</script>