این فقط یک مثال است
index.php
کد HTML:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Untitled</title>
<script type="text/javascript">
function result(value){
if(value.length==0){
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("result").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","result.php?id="+value,true);
xmlhttp.send(null);
}
</script>
</head>
<body >
<div align="center" >
<select name="number_query" onchange="result(this.value);">
<option value="1">yazd</option>
<option value="2">tehran</option>
<option value="3">esfahan</option>
</select>
</div>
<br>
<div align="center" id="result">
<select>
<option>mehriz</option>
<option>maybod</option>
<option>yazd</option>
</select>
</div>
</body>
</html>
result.php
کد HTML:
<?php
$id=$_GET["id"];
print '<select>';
if($id=='1')
{
print '<option>mehriz</option>';
print '<option>maybod</option>';
print '<option>yazd</option>';
}
else if($id=='2')
{
print '<option>1</option>';
print '<option>2</option>';
print '<option>3</option>';
}
else if($id=='3')
{
print '<option>a</option>';
print '<option>b</option>';
print '<option>c</option>';
}
print '</select> ';
?>