Populating a List inside a grid

Basically what i need is for a dropdown window insided of a grid to be populated with data from the same xml file i am using to populate the grid with. Does anyone know how to do this?

below is code i found which works for me if the information in the drop down was to remain static for each row of the grid, which it does not.

var data1 = ["Email","Phone","FedEX","USPS"];

var list1 = new AW.UI.List;
list1.setItemText(data1);
list1.setItemCount(data1.length);

var obj = new AW.UI.Grid;

obj.setCellData("cell");
obj.setHeaderText("header");
obj.setColumnCount(10);
obj.setRowCount(10);

obj.setCellEditable(true);

obj.setCellTemplate(new AW.Templates.Combo, 1);

obj.setPopupTemplate(list1, 1);

document.write(obj);