// JavaScript Document
function check_answer(currentid, checkname, num_answer){
	for(i=1; i<=num_answer; i++){
		try{
			document.getElementById("quest"+checkname + "_" + i).checked=false;
		}
		catch(e){}
	}
	document.getElementById(currentid).checked=true;
	document.getElementById("check_poll").value = 1;
}

function submit_poll(){
	if(document.getElementById('check_poll').value == 0){
		alert("Ban phai chon cau tra loi !");
		return;
	}
	document.tracnghiem.submit();
}