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);