Fro this you need to put a code in show report button click event like this....
protected void btnShowReport_Click(object sender, EventArgs e)
{
if (A.Checked == true)
{
ReportDocument rpt = new ReportDocument();
rpt.Load("CrystalReport1.rpt");
CRPTViewer.ReportSource = rpt;
CRPTViewer.RefreshReport();
}
if (B.Checked == true)
{
ReportDocument rpt = new ReportDocument();
rpt.Load("CrystalReport2.rpt");
CRPTViewer.ReportSource = rpt;
CRPTViewer.RefreshReport();
}
}