mark entry form issue in web form

            I am developing school management system using asp.net. In that i have to develop mark entry form. In mark entry form I have a three combobox column for medium and class and exam. based on the exam and class i want to bind the student and subject in the gridview with editable cell.format is

Name       RollNo              Tamil                English

    IM        EM        IM      EM 

Ranjith    125000         20       70         25      71 

Karthick   125001        22        72        22       75

IM -Internal Mark 

EM - External Mark

In web application gridview cells are non editable by default. I need to set edit button on the row to edit.but i want  all cell corresponding to mark and student must be editable without using rowedit event.