// return the value of the radio button that is checked
// return an empty string if none are checked, or
// there are no radio buttons
function radioGetCheckedValue(radioObj) {
	if(!radioObj)
		return "";

	// alert('radioGetCheckedValue : radioObj not null');

	var radioLength = radioObj.length;

	// alert('radioGetCheckedValue : radioObj.length = '+radioLength);

	if(radioLength == undefined){
		if(radioObj.checked)
			return radioObj.value;
		else
			return "";
	}

	// alert('radioGetCheckedValue : radioObj has length');

	for(var i = 0; i < radioLength; i++) {
		if(radioObj[i].checked) {
			return radioObj[i].value;
		}
	}

	// alert('radioGetCheckedValue : returning blank');

	return "";
}

// set the radio button with the given value as being checked
// do nothing if there are no radio buttons
// if the given value does not exist, all the radio buttons
// are reset to unchecked
function radioSetCheckedValue(radioObj, newValue) {
	if(!radioObj)
		return;

	var radioLength = radioObj.length;
	if(radioLength == undefined) {
		radioObj.checked = (radioObj.value == newValue.toString());
		return;
	}

	for(var i = 0; i < radioLength; i++) {
		radioObj[i].checked = false;
		if(radioObj[i].value == newValue.toString()) {
			radioObj[i].checked = true;
		}
	}
}