Forms Data Controls :: Attempting To Add A Drop Down Menu To A Gridview?

I am attempting to add a drop down menu to a gridview once the user slects the "Edit" button for the gridview. I want the value, before the edit button is selected, to be the value in one table and once the "Edit" button is selected I want to show values from another table in a drop down menu so the user only has specific values to edit the selected row with.

2 tables:

table 1) tbl_FormalizeRawData - List of columns from a table inside a database
table 2) tbl_StandardColumns - list of standard column names for system tables.

I want the user to be able to specify which raw non standard columns corospond to the standardized system table columns.

example:

RawClientTable.MiscColumn1 = SystemTable.Member_First_Name
RawClientTable.MiscColumn2 = SystemTable.Member_Last_Name
my code for the gridview is as follows. I am looking to see what else I need to do in order to allow the gridview to be edited on the final column by a dropdown menu populated by a seperate table but display the item in the main table with all the non standard column names:

[Code]....

a boot in the rright direction. I attempted to go through the "Walkthrough: Displaying a Drop-Down List While Editing in the GridView Web Server Control" at the website[URL] as it was geared toward a drop down menu added to a gridview both using the same table.