Comments by ATjong (Top 4 by date)

Agree with RyanDev. Try to structure your question.
Which controls do you have? (how many and types)
What is the trigger for your action? (user clicks,binding etc)
What has to happen then?
What happens now?

As far as I know crystal reports work with a data schema, which only can be filled with a dataset with corresponding columns. It's not possible to fill each of the columns of the report's schema separately.

Did you check with sql profiler which query gets executed? is TNumID your primary key? Is it possible that there is a row where TNumID = null?