function addOption(oListbox, sName, sValue) {
	var oOption = document.createElement("option");
	oOption.appendChild(document.createTextNode(sName));
	if (arguments.length == 3) {
		oOption.setAttribute("value", sValue);
	}
	oListbox.appendChild(oOption);
}
function cleanSelect(selector) {
	var select=document.getElementById(selector);
	if( select && select.length > 0 ){
		for (var i = select.length - 1; i>=0; i--) {
			select.remove(i);
		}
	}
}