AXAPTA - Catch tabbed dialog enter and exit

Use  pageActivated() for catch enter tabbed dialog, use allowPageDeactivate() for catch exit. I tried to use Lostfocus() and GotFocus() with no success.

AXAPTA runbase dialog

void clicked()

{

    Dialog      dialog;

    DialogField DEmplId;

    DialogField DApp;

    DialogField DAppDesc;

    ;

    dialog = new Dialog("@SYS108667");

    DApp     = dialog.addField(typeId(B_Approval));

    DAppDesc = dialog.addField(typeId(Description));

    DEmplId  = dialog.addField(typeId(EmplId));

    DApp.value(B_RepairJournalPartsChangeLines.Approval);

    DAppDesc.value(B_RepairJournalPartsChangeLines.ApprovalDescription);

    DEmplId.value(SysCompanyUserInfo::find(CurUserId()).EmplId);

    dialog.run(); // show

    if (dialog.closedOK())

    {

        ttsbegin;

        B_RepairJournalPartsChangeLines.Approval            = DApp.value();

        B_RepairJournalPartsChangeLines.ApprovalDescription = DAppDesc.value();

        B_RepairJournalPartsChangeLines.ApproveEmplId       = DEmplId.value();

        element.redraw();

        ttscommit;

    }

}