Master Table Data

I am trying to show the Master Table data on the print page and have used the following code:

str = "select FullName from AUD_USERS where StaffNumber='" & Session(strTableName & "_masterkey1") & "'"

and get a Data type mismatch in criteria expression. error
if I change the code to be :

str = "select FullName from AUD_USERS where StaffNumber=200073"

I get the correct name displayed
Any ideas how to just pick up master table data on a print page?