Ok So I have made some modifications based on teleriks suggestion but now the grid is not readling the lines
The goal I need to achieve is to pass the header id into the lines and then on my view details button pass the id to the popup so that it is their for saving saving from the main window is not the modal i want to follow which was a suggestion in support ticket.
My Entire activity controller.
My Model of detail and lines
As you see above activity lines is a ICollection of activity header All i want to be able to do is a simple crud on the lines within the popup.