function createRequestObject(){
	var request_o; //declare the variable to hold the object.
	var browser = navigator.appName; //find the browser name
	if(browser == "Microsoft Internet Explorer"){
		/* Create the object using MSIE's method */
		request_o = new ActiveXObject("Microsoft.XMLHTTP");
	}else{
		/* Create the object using other browser's method */
		request_o = new XMLHttpRequest();
	}
	return request_o; //return the object
}
var http = createRequestObject(); 
function getModel(selObj){
	http.open('get', 'getmodel.php?id='+ selObj.options[selObj.selectedIndex].value);
	http.onreadystatechange = handleModel; 
	http.send(null);
}
function handleModel(){
	if(http.readyState == 4){
		var response = http.responseText;
		document.getElementById('Model_Select').innerHTML = response;
		document.getElementById('Trim_Select').innerHTML = '<SELECT name="trim" disabled><option value="0">---- ทั้งหมด ----</option></select>';
	}
}
function getTrim(selObj){
	http.open('get', 'gettrim.php?id='+ selObj.options[selObj.selectedIndex].value);
	http.onreadystatechange = handleTrim; 
	http.send(null);
}
function handleTrim(){
	if(http.readyState == 4){
		var response = http.responseText;
		document.getElementById('Trim_Select').innerHTML = response;
	}
}

function getBound(selObj){
	http.open('get', 'getbound.php?id='+ selObj.options[selObj.selectedIndex].value);
	http.onreadystatechange = handleBound; 
	http.send(null);
}
function handleBound(){
	if(http.readyState == 4){
		var response = http.responseText;
		document.getElementById('Bound_Select').innerHTML = response;
	}
}