เอา Dropdown list Ajax+php+mysql & php+SqlServer2008+ajax+sql_srv function มาแบ่งกันใช้ เป็นอีกแนวทาง ใช้งานง่ายมาก

<?php 
 header("Content-Type: text/html; charset=tis-620");    

	echo "<form name=sel>";
	 echo "จังหวัด : <font id=province><select   onkeypress='return handleEnter(this, event)' >";
	echo "<option value='0'>--------------------</option>" ;
	echo "</select></font><br><br><br>";
	
	echo "อำเภอ : <font id=amper><select  onkeypress='return handleEnter(this, event)' >";
	echo "<option value='0'>--------------------</option> " ;
	echo "</select></font><br><br><br>";
		
	echo "ตำบล : <font id=tumbon><select onkeypress='return handleEnter(this, event)' >";
	echo "<option value='0' diable>--------------------</option> " ;
	echo "</select></font>";

	?> 
<script language=Javascript>
function Inint_AJAX() {
   try { return new ActiveXObject("Msxml2.XMLHTTP");  } catch(e) {} //IE
   try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch(e) {} //IE
   try { return new XMLHttpRequest();          } catch(e) {} //Native Javascript
   alert("XMLHttpRequest not supported");
   return null;
};

function dochange(src, val) {
     var req = Inint_AJAX();
     req.onreadystatechange = function () { 
          if (req.readyState==4) {
               if (req.status==200) {
                    document.getElementById(src).innerHTML=req.responseText; //รับค่ากลับมา
               } 
          }
     };
     req.open("GET", "sqlsrv_list_location.php?data="+src+"&val="+val); //สร้าง connection
     req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=tis-620"); // set Header
     req.send(null); //ส่งค่า
}

window.onLoad=dochange('province', -1);          
</script>
 
  

<?php
     //กำหนดให้ IE อ่าน page นี้ทุกครั้ง ไม่ไปเอาจาก cache lklkk
     header ("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
     header ("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
     header ("Cache-Control: no-cache, must-revalidate");
     header ("Pragma: no-cache");
     header("content-type: application/x-javascript; charset=tis-620");

        $data=$_GET['data'];
       $val=$_GET['val'];
     //ค่ากำหนดของ ฐานข้อมูล
	$serverName = "localhost";
	$connectionInfo = array( "Database"=>"thailand", "UID"=>"sa", "PWD"=>"abc+123");
	$conn = sqlsrv_connect( $serverName, $connectionInfo);
	if( $conn === false ) {
		 die( print_r( sqlsrv_errors(), true));
	}
 
     if ($data=='province') { 
          echo "<select name='province'  onChange=\"dochange('amper', this.value)\"  onkeypress='return handleEnter(this, event)'  >";
				$sql = "SELECT    PROVINCE_ID, PROVINCE_CODE, PROVINCE_NAME, GEO_ID
				FROM         province
				ORDER BY PROVINCE_NAME";
				$stmt = sqlsrv_query( $conn, $sql);
				if( $stmt === false ) {	 die( print_r( sqlsrv_errors(), true));}
				echo "<option value='' >เลือก</option> " ;		
				while( $obj = sqlsrv_fetch_object( $stmt)) { 
					echo "<option value='$obj->PROVINCE_ID' >$obj->PROVINCE_NAME</option> " ;	 
				} 
	echo "</select>\n";   
     } else if ($data=='amper') {
          echo "<select name='amper'   onChange=\"dochange('tumbon', this.value)\"  onkeypress='return handleEnter(this, event)'  >";
		    	 	$sql = " SELECT  AMPHUR_ID, AMPHUR_CODE, AMPHUR_NAME, GEO_ID, PROVINCE_ID
					FROM         amphur
					WHERE     (PROVINCE_ID ='$val')
					ORDER BY AMPHUR_NAME";
				$stmt = sqlsrv_query( $conn, $sql);
				if( $stmt === false ) {	 die( print_r( sqlsrv_errors(), true));}
				echo "<option value='' >เลือก</option> " ;	
				while( $obj = sqlsrv_fetch_object( $stmt)) { 
					echo "<option value='$obj->AMPHUR_ID' >$obj->AMPHUR_NAME</option> " ;	 
				} 
	     echo "</select>";  	  
     } else if ($data=='tumbon') {
         echo "<select  name='tumbon'    onChange=\"dochange('qlocate', this.value)\"  onkeypress='return handleEnter(this, event)'   >";
		$sql = "  SELECT  DISTRICT_ID, DISTRICT_CODE, DISTRICT_NAME, AMPHUR_ID, PROVINCE_ID, GEO_ID
				FROM         district
				WHERE     (AMPHUR_ID ='$val')
				ORDER BY DISTRICT_NAME";
				$stmt = sqlsrv_query( $conn, $sql);
				if( $stmt === false ) {	 die( print_r( sqlsrv_errors(), true));}
				echo "<option value='' >เลือก</option> " ;	
				while( $obj = sqlsrv_fetch_object( $stmt)) { 
					echo "<option value='$obj->DISTRICT_ID' >$obj->DISTRICT_NAME</option> " ;	 
				} 
		 echo "</select>\n";  	 
}    
?>