Ajax DataBase Create Code

<html>
<head>
<script type="text/javascript">
function showCustomer(str)
{
if (str=="")
  {
  document.getElementById("txtHint").innerHTML="";
  return;
  }
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open("GET","getcustomer.asp?q="+str,true);
xmlhttp.send();
}
</script>
</head
<body>
<form>
<select name="customers" onchange="showCustomer(this.value)">
<option value="">Select a name:</option>
<option value="Ali">Ali</option>
<option value="Ahmed ">Ahmed</option>
<option value="Zain">zain</option>
</select>
</form>
<br />
<div id="txtHint">Customer info will be listed here...</div>
</body>
</html>