Edit grid view in other page using imagebutton

hi im trying to edit my gridview row in other page where i have controls like textboxes and buttons,radiobuttons.
the requirement is like i need to keep image for my button its not possible with autogenerate edit
so im using one normal button and i want to take these values using querystring not in session.
becoz i have a primary key using that i want to edit record.
plz suggest the code. the below code is working fine for autogenerate edit.
but i want to write the same kind of functionality for my button with image.
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protected void grdEmployeesEdit_RowEditing(object sender, GridViewEditEventArgs e)
    {
       grdEmployeesEdit.EditIndex = e.NewEditIndex;
       string lid;    
        Label objEmp = (Label)grdEmployeesE ...