function validate(obj)
{
	has_answer = false;
	for (i = 0; i < obj.elements['ans[]'].length; i++)
	{
		if (obj.elements['ans[]'][i].checked == true)
		{
			has_answer = true;
			break;
		}
		
	}
	if (!has_answer)
	{
		alert("You must select at least one option as answer");
		return false;
	}
}