Display multiple Reports in same Report Viewer

I am trying to display two rdlc report in same reportviewer but facing some problem with datasource. Can anyone help me?
My code is:
aspx page
form id="form1" runat="server"> <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True"> <asp:ListItem>Ministry_Wise_Pre_Post_06</asp:ListItem> <asp:ListItem>MInistry_PPO_Wise_Pre_Post_06</asp:ListItem> </asp:DropDownList> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" /> <br /> <br /> &nbsp;<div> <asp:ScriptManager ID="ScriptManager1" runat="server"> </asp:ScriptManager> <rsweb:ReportViewer ID="ReportViewer1& ...