>Localhost is the name of the web service. Check your web references (which you'll find in the project explorer) and replace the word localhost with the name of the web service reference you added.

This works:

webViewer1.reportsource = @"c:\webreports\AcctProfile.rpt";

This gives an invalid report source error:

webViewer1.reportsource = webapplication1.AcctProfileService();

Where AcctProfileService is a web service generated from c:\webreports\AcctProfile.rpt in the project webapplication1.

Any clues?