Since the report is being built from a dataset, then all the work is done in .NET. Thus, this isn't really a crystal reports question. If you're dataset is based on pure SQL, then you would have to embed the combobox value into the WHERE clause of the SQL statement. If you're using a stored procedure, then pass it as a parameter when you call the stored procedure.

After this is done, you can go into debug mode and check what is in the dataset to see if it got the records you expected it to return. Then pass the dataset to your report. But as you can see, all the work is done PRIOR to passing the dataset to the report.

If you need help on using .NET with Crystal Reports, you could check out my book which tells you everything you need to know:
Crystal Reports Encyclopedia v2




Edited by BrianBischof - 08 Oct 2009 at 6:51pm