One thing to keep in mind when parsing XML from a variable or a data node is that attributes are considered to be a node of the parent. So, child-elements will not necessarily start at (0) if the parent has an attribute. The attribute(s) will be considered before the children.
This sample demonstrates a few methods of retrieving XML data including the population of a drop-down from XML on the form. The data is provided in a text box and parsed using the XMLData.parse method so that you can change the data and watch the results in real-time.