how to compaire row of selected cell of grid view two time .

 i have upload excel file on gridview.

how to check if i select cell value two times form gridview there selected row are same or not .means i have select multiple cell value from girdview  there color is red and another time i have select multiple cell value on same grid .how to compaire both selected cell rows are same.if selected rows of both are not samethen show msg.