Seems like you are trying to bind the GridView from Markup side (.aspx ) as well as using code behind.( .aspx.cs )
Choose any one way only to bind the grid.
1.) If you bind gridview from code behind then remove the DataSourceId
property from grid view from markup. Change below code:
<asp:gridview id="GdvOrganization" runat="server" autogeneratecolumns="False"
DataSourceID="MyDataSource">
to
<asp:gridview id="GdvOrganization" runat="server" autogeneratecolumns="False">
2.) if you prefer to bind from markup side then you have to remove the c# code to bind the grid.
Still if above 2 steps doesn't interest you, try below trick ( Recommended ?? )
GdvOrganization.DataSource = ds;
GdvOrganization.DataSourceID = String.Empty;
GdvOrganization.DataBind();