// JavaScript Document
var QH = new Array(100);
var a=0;
for(a;a<100;a++){
	QH[a] = new Array();
}
function create_arr(i,j,name){
	QH[i][j]=name;
}
//tao cac option quan huyen
function create_option(id,name,value,idselect){
	var y=document.createElement('option');
	var x=document.getElementById(idselect);
	y.text=name;
	y.value=value;
	y.id=id;
	try{
		x.add(y,null); // standards compliant
	}
	catch(ex){
		x.add(y); // IE only
	}
}
//xoa cac option
function remove_option(idselect)
	{
		var x=document.getElementById(idselect);
		var i=x.length-1;
		for(i;i>0;i--){
			x.remove(i);
		}
	}
//Thay doi tinh
function changetinh(id,idselect){
	remove_option(idselect);
	var l=document.getElementById(id);
	var x=l.options[l.selectedIndex].id;
	var n=QH[x].length;
	var i=0;
	var name;
	for(i;i<n;i++){
		name=QH[x][i];
		create_option(i,name,name,idselect);
	}
}
//Cac option da select
function selectoption1(op,id,idselect1,idselect2){
	var x=document.getElementById(idselect1);
	x.selectedIndex=op;
	changetinh(id,idselect2);
}
function selectoption2(op,idselect){
	var x=document.getElementById(idselect);
	x.selectedIndex=op;
}