Unable to cleare report viewer or datasource

Hi, all,

I am using report viewer control to display report(rdlc). I am using same report viewer for two buttons(for pdf, and excel)

I am taking two different rdlcs for pdf and excel. I am displaying some extra columns in excel.

Now problem is, I am unable to clear the report viewer. ie. after previewing the excel, when i preview for pdf, i am getting old report with excel extra colums.

How can i clear the report viewer.

I am using following code to clear report viewer data,

Dim rep As LocalReport = ReportViewer1.LocalReport

rep.DataSources.Clear()

and  

myDataSet.Clear(), but still i am facing the problem

Regards,

Naren