Updaing A GridView At Runtime

Hi

 I am binding SQLdatasource with the Gridview at runtime that works fine, but i have mentioned the update command as well, but grid is not updating, there is no error, but after clicking update, no thing happens and grid returns to last state.

Part of code is :

void btnshowdata_click(){

SqlDataSource1.SelectCommandType = SqlDataSourceCommandType.StoredProcedure;

SqlDataSource1.SelectCommand = "dbo.getAllOutstanding";

SqlDataSource1.UpdateCommand = "UPDATE SPS_Oustandings SET Status = @Status, Comments = @Comments WHERE (Inv_No = @Inv_no)";

grid.DataBind();

}

datasource is already attached to grid, but its select query is chaning at button click. At design time binding update works but when i click the button binding(select quesry) is changed, after that update is not working.

 

Any help?

Thanks