ReportViewer

Question

i have created a dataset(ReportingDataset.xsd) and in that i have added table adapter through existing stor proc..
  I also have created 4 reports and dragged and the data.. I have 1 reportViwer. My issuse is how to bind these 4 reports in 1 report viwer.

I have a dropdown where i statically added 4 report.

Cover Report:</td>

<td><asp:DropDownList ID="ddlCoverReprt" runat="server" Width="200" AppendDataBoundItems="true">

   <asp:ListItem Text="-- Select CoverReport --" Value="-1" Selected="True" />

   <asp:ListItem Text="Report by Coverage Count" Value="Report by Coverage Count"></asp:ListItem>

   <asp:ListItem Text="Press Release" Value="Press Release"></asp:ListItem>

   <asp:ListItem Text="Report By Company" Value="Report By Company"></asp:ListItem>

   <asp:ListItem Text="Normal Report" Value="Normal Report"></asp:ListItem>

  <%-- <asp:ListItem Text="Print Preview" Value="Print Preview"></asp:ListItem>--%>

</asp:DropDownList>

<asp:Button ID="btnReport" runat="server" Text="Generate Report" 

        ValidationGroup="fetchEntryGroup" onclick="btnReport_Click"></asp:Button>

On differnt report my report should be genereted....
Thanks in Advance