var nbFormSubmit = 0;

function preventDoubleSubmit() {
	return (++nbFormSubmit == 1);
}

//empty a field if the value is equals to fieldContent param
function emptyField(fieldId, fieldContent){
	try {
	 	var aField = document.getElementById(fieldId);
	    if((aField != null) && (fieldContent == aField.value)){
	         aField.value='';
    	}
    }catch (e){}
}

// returns the value of the selected radio button or "" if no button is selected
function getSelectedRadioValue(buttonGroup) {
	var i = getSelectedRadio(buttonGroup);
	if (i == -1) {
		return "";
	} else {
		// Make sure the button group is an array (not just one button)
		if (buttonGroup[i]) { 
			return buttonGroup[i].value;
		} else { // The button group is just the one button, and it is checked
			return buttonGroup.value;
		}
	}
}