//initial varable
//list_model=2 for dpl2
//list_model=3 for dpl3
//list_model=4 for dpl4
//list_model=5 for dpl4will show model data

var http_request = false;

var l1=0;
var l2=0;
var l3=0;
var l4=0;

var list_model=0;

var timerID;


function body_load() 
{  	
	var dpl1;
	var dpl2;
	var dpl3;
	var dpl4;
		
	
	dpl1=document.getElementById("dpl_l1");
	dpl2=document.getElementById("dpl_l2");
	dpl3=document.getElementById("dpl_l3");
	dpl4=document.getElementById("dpl_l4");
	
	dpl1.onchange = dpl_l1_change;
	dpl2.onchange = dpl_l2_change;
	dpl3.onchange = dpl_l3_change;

	  
	dpl2[0] = new Option(str_s_p_line,"0");
	dpl3[0] = new Option(str_s_p_series,"0");
	dpl4[0] = new Option(str_s_p_series4,"0");
	
	timerID = setInterval("hide_loading()",500);
	
}

function dpl_l1_change()
{
 
 	var dpl2;
	var dpl3;
	var dpl4;
	
	dpl2=document.getElementById("dpl_l2");
	dpl3=document.getElementById("dpl_l3");
	dpl4=document.getElementById("dpl_l4");
	
	
	dpl2.disabled=true;
	dpl3.disabled=true;
	dpl4.disabled=true;
	
	dpl2.length=0;
	dpl2[0] = new Option(str_s_p_line,"0");
	
	dpl3.length=0;
	dpl3[0] = new Option(str_s_p_series,"0");
	
	dpl4.length=0;
	dpl4[0] = new Option(str_s_p_series4,"0");
	

	show_loading();
	setTimeout("load_l2()",500);
}

function dpl_l2_change()
{
	var dpl3; 
	var dpl4
	dpl3=document.getElementById("dpl_l3");
	dpl4=document.getElementById("dpl_l4");
	
	dpl3.disabled=true;
	
	dpl3.length=0;
	dpl3[0] = new Option(str_s_p_series,"0");
	dpl3.disabled=false;
	
	
	dpl4.disabled=true;
	
	dpl4.length=0;
	dpl4[0] = new Option(str_s_p_series4,"0");
	//dpl4.disabled=false; 
	

	show_loading();
	setTimeout("load_l3()",500);
	
}


function dpl_l3_change()
{
	var dpl4
	dpl4=document.getElementById("dpl_l4");
	dpl4.disabled=true; 	
	dpl4.length=0;
	
	dpl4[0] = new Option(str_s_p_series4,"0");
	
		
	show_loading();
	setTimeout("load_l4()",500);
}




//--------------------------------------------------
//load data for level2

function load_l2()
{	
	
	var dpl1;	
	dpl1=document.getElementById("dpl_l1");	
	l1=dpl1.value;
			
	list_model=2;
		
	send_request("loaddata.aspx?l1="+l1);				
	
	
	load_l3();		
}

//--------------------------------------------------
//load data for level3
function load_l3()
{	
	var dpl2;
	dpl2=document.getElementById("dpl_l2");
	l2=dpl2.value;
	
	list_model=3;		
	send_request("loaddata.aspx?l2="+l2);
		
	load_l4();
	
}

//--------------------------------------------------
//load data for level4
function load_l4()
{
	var dpl3;
	dpl3=document.getElementById("dpl_l3");
	l3=dpl3.value;
	
	list_model=4;		
	send_request("loaddata.aspx?l3="+l3);	
	
	hide_loading();
} 


//--------------------------------------------------


function send_request(url) 
{		
	http_request = false;			//初始化、指定处理函数、发送请求的函数
	
	if(window.XMLHttpRequest) //开始初始化XMLHttpRequest对象
	{ 			
		http_request = new XMLHttpRequest();				//Mozilla 浏览器
		if (http_request.overrideMimeType) 
		{				
			http_request.overrideMimeType('text/xml');//设置MiME类别
		}
	}
	else if (window.ActiveXObject) 
	{ 
		// IE浏览器
		try 
		{
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} 
		catch (e) 
		{
			try 
			{
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} 
			catch (e)	{}
		}
	}
	if (!http_request) 
	{
		window.alert("Can nont create XMLHttpRequest new object."); // 异常，创建对象实例失败
		return false;
	}
	http_request.onreadystatechange = processRequest; // 确定发送请求的方式和URL以及是否同步执行下段代码
	
	http_request.open("GET", url, false);
	http_request.send(null);
}
	
// 处理返回信息的函数
function processRequest() 
{
    if (http_request.readyState == 4) 
    { 
    	// 判断对象状态    	
        if (http_request.status == 200) 
        {          
			var dpl1;
			var dpl2;
			var dpl3;
			var dpl4;
			
			var lbl;
			dpl1=document.getElementById("dpl_l1");
			dpl2=document.getElementById("dpl_l2");
			dpl3=document.getElementById("dpl_l3");
			dpl4=document.getElementById("dpl_l4");
			lbl=document.getElementById("lbl_model");
        
			xmldoc = new ActiveXObject("Microsoft.XMLDOM");
			xmldoc.loadXML(http_request.responseText); 
			var dataArray = xmldoc.getElementsByTagName('Table1'); 
			var dataArrayLen = dataArray.length;
			for (var i=0; i<dataArrayLen; i++)
			{

				get_id=dataArray[i].childNodes[0].text;
				get_value=dataArray[i].childNodes[1].text;
				if (l1!=0&&list_model==2) //load level 2
				{
					dpl2.disabled=false;
					dpl2.add(new Option(get_value,get_id));					
				}
				else if(l2!=0&&list_model==3) //load level 3
				{
					dpl3.disabled=false;
					dpl3.add(new Option(get_value,get_id));
				}
				else if(l3!=0&&list_model==4) //load level 4
				{
					dpl4.disabled=false;
					dpl4.add(new Option(get_value,get_id));
				}							
			}
        } 
        else 
        { 
            alert("You request page happen exception.");//页面不正常
        }
    }
}

//---------------------------------------------------------------------------
//for loading hide and show
function show_loading() 
{ 
	IE = (document.all && navigator.userAgent.indexOf("Opera") == -1)
	if (IE) 
	{
		var load_object;
		load_object=document.getElementById("loading")
		load_object.style.display = "inline";
		load_object.style.pixelTop = (document.body.clientHeight/2)-(document.getElementById("loading").offsetHeight/2)+(document.body.scrollTop);
		load_object.style.pixelLeft = (document.body.clientWidth/2)-(document.getElementById("loading").offsetWidth/2)+(document.body.scrollLeft);
	}
} 

function hide_loading() 
{
	clearInterval(timerID);
	document.getElementById("loading").style.display = "none";
}
//---------------------------------------------------------------------------