Cannot Access Expression Builder

[meliorexi]

Hi

I need to calculate an invoice amount using information from various tables in my database. I prefer to do it in Expression Builder but can't seem to access it.

When I right click on the Invoice Amount control (in design view of the form) and select Build Event (it does not allow me to select Build)it just opens the Macro Design View. Occasionally it allows be to choose between Macro Builder and Code Builder (although I'm not sure what trigers this) but never gives me the option of Expression Builder.

Any ideas?

 

[meliorexi]

Sorry, I should specify that I am using SQL Server with Access XP as the client (therefore it is an Access Project, not an Access database).