HI,
I think you fill crystal report through wizard.
try to fill crystal report with c# code.
it does not given this prompt.
Like this:-
ReportDocument rpdoc = new ReportDocument();
rpdoc.Load(Server.MapPath("~/reports/crystalreportname.rpt"));
DataSet ds = {Your dataset/datasourse}
rpdoc.SetDataSource(ds.Tables[0].DefaultView);
CrystalReportViewer1.ReportSource = rpdoc;
i hope it worked.Remember marked answer as correct if right!!..
thanks