How to read Menu Custom Field values from Javascript API?

Content

Hi All,

I have tried reading Menu type Custom Field values. But I am getting an undefined error. I am using following code block:

Version

Nov 2014

Code Snippet

             <script type="text/javascript">
function onbeforesave()
{
	var inc = window.external.Incident;
	var Prov = "";
	var ProvId = inc.GetCustomFieldByName("c$test_menu_field");
	alert("Provider ID : " +ProvId);
	var ProvLbls = inc.GetNameValues("c$test_menu_field");
	alert("Provider labels : " +ProvLbls);
	xmlDoc.loadXML(ProvLbls);
	var x = xmlDoc.getElementsByTagName("Item");
	for (i = 0; i < x.length; i++) 
	{
		var attlist=x.item(i).attributes;
		var att=attlist.getNamedItem("Id");
		if (att.value==ProvId) 
		{
			Prov = attlist.getNamedItem("Name").value;
		}
	}
}
</script>