How to set focus custom image button after click that button

My problem is ..

I want to set focus at custom image button.

If I click that button, a form will be open,after I close that form, the button that I clicked should be on focus.

                                                   ImageUrl="img/CM_b2_detail.gif"
                          AlternateText="Detail"
                          CommandName="Dtil">

                                                   ImageUrl="img/CM_b2_delete.gif"
                          AlternateText="Delete"
                          CommandName="Delete"
                          ClientFocusScript="defaultFunctionKeyBody"
                          ClientClickScript="delRowConfirmDialog">











                                                   ImageUrl="img/CM_b2_detail.gif"
                          AlternateText="Detail"
                          CommandName="Dtil"
                          ClientFocusScript="defaultFunctionKeyEdit"
                          Visible=true>

                                                   ImageUrl="img/CM_b2_update.gif"
                          AlternateText="Update"
                          CommandName="Update"
                          ClientFocusScript="defaultFunctionKeyEdit"
                          ClientClickScript="updateSoRowCheck">

                                                   ImageUrl="img/CM_b2_delete.gif"
                          AlternateText="Delete"
                          CommandName="Delete"
                          ClientFocusScript="defaultFunctionKeyEdit"
                          ClientClickScript="delRowConfirmDialog">

Button is created like that.