//category methods
	function Category(id,title) {
		this.id = id;
		this.title=title;
		this.boardlist=new Array();
		this.addBoard=addBoard;
		this.getOptions = getOptions;
	}	
	
	function addBoard(board) {
		this.boardlist = this.boardlist.concat(board);
	}
	
	function getOptions() {
		var tmp = new Array();
		for(var i=0; i < this.boardlist.length;i++) {
			var b = this.boardlist[i];
			tmp[i]= b.getOption();
		}
		return tmp;
	}
	
	//board methods
	function Board(catid,id,title,total) {		
		this.catid=catid;
		this.id=id;
		this.title=title;
		this.getOption=getOption;
	}
		
	function getOption() {
		return new Option(this.title,this.id);		
	}
		
	function changeCategory(list) {	
		if (list.selectedIndex<=0) {
			catForm.options[0].selected=true;
    		var len = boardForm.options.length;
    		for (var i=len-1;i>0;i--){
    			boardForm.options[i]=null;
    		}					
		}
        else {
    		var boards = catArr[list.selectedIndex-1].getOptions();
    		var len = boardForm.options.length;
    		for (var i=len-1;i>0;i--){
    			boardForm.options[i]=null;
    		}		
    		for (var i=0;i<boards.length;i++) {
    			boardForm.options[i+1]=boards[i];
    		}
		}
		boardForm.options[0].selected=true;
	}
		
	function selectBoard(catid,bid) {
		for(var i=0;i<catForm.length;i++) {
			if (catForm.options[i].value==catid) {
				//alert("get Category");
				catForm.options[i].selected=true;
				changeCategory(catForm);
				break;			
			}			
		}				
		for(var i=0;i<boardForm.length;i++) {
			if (boardForm.options[i].value==bid) {
				//alert("get Board");
				boardForm.options[i].selected=true;				
				break;
			}			
		}		
	}	
	
	//static methods	
	var catArr = new Array();
	var cur;
	
	

cur = new Category('21','警务动态');catArr = catArr.concat(cur);cur = new Category('22','案例剖析');catArr = catArr.concat(cur);cur = new Category('24','办事指南');catArr = catArr.concat(cur);cur.addBoard(new Board('24','29','车管业务'));cur.addBoard(new Board('24','30','驾管业务'));cur.addBoard(new Board('24','31','秩序管理'));cur.addBoard(new Board('24','32','违法处理'));cur.addBoard(new Board('24','33','事故处理'));cur.addBoard(new Board('24','34','收费标准'));cur.addBoard(new Board('24','35','表格下载'));cur = new Category('25','交通法规');catArr = catArr.concat(cur);cur = new Category('29','网上学习班');catArr = catArr.concat(cur);cur = new Category('30','交通标志');catArr = catArr.concat(cur);cur.addBoard(new Board('30','36','警告标志'));cur.addBoard(new Board('30','37','禁令标志'));cur.addBoard(new Board('30','38','指示标志'));cur.addBoard(new Board('30','39','指路标志'));cur.addBoard(new Board('30','40','旅游标志'));cur.addBoard(new Board('30','41','道路施工安全标志'));cur.addBoard(new Board('30','42','指示标线'));cur.addBoard(new Board('30','43','禁止标线'));cur.addBoard(new Board('30','44','警告标线'));cur = new Category('31','安全点滴');catArr = catArr.concat(cur);
       

	//init catform
	
	var catForm = document.myform.class1;
	var boardForm = document.myform.class2;
	for (var i=0;i<catArr.length;i++) {
		catForm.options[i+1]=new Option(catArr[i].title,catArr[i].id);
	}
	changeCategory(catForm);
	//init		
// -->