function valButton(btn) {
//    alert(btn.length);
    var valid = false;
    for (var i=btn.length-1; i > -1; i--) {
//	    alert(btn[i].value + ", " + btn[i].checked);
        if (btn[i].checked) {
//		  alert("a button was checked!");
		  valid = true;
		}
    }
    if (valid) {
	  return true;
	} else { 
	  alert("You must choose one option before you can submit your vote.");
	  return false;
	}
}