[Solved] Incompatible error in string and uniqueidentifier in ASP.Net

I have a recordset that I bring into an ASP.Net DropDownList.  When an item is selected it adds a where clause to the SQL Statement and refreshes the data. 

The problem is that the field used for the where clause is a uniqueidentifier.  The same field is used for the where clause but I'm getting an error saying the 2 are incompatible. 

I'm assuming that the reason is that the dropdown box is seeing the field as a string not a uniqueidentifier.  I need to convert it back to a uniqueidentifer so the where clause will work. 

Any idea how I can do that