i have a xamdatagrid. I need to validate while editing the isverifed cell. The Isverified cell is the only cell that the user is allowed to edit.  It is a string that is validated against another string from another cell in the same row in the grid.  basically i need this to run a check against another value when the user is editing it, and if the validation passes, i need to change the image in the verfied cell from an image of an X to and image of a check mark