[Stitch_MS]

Можно как-то так:

public void verifySomeFormNotAlreadyOpen()
{
    ObjectIdent objIdent = infolog.globalCache().get(classstr(SomeClassResponsibleForLocking), curext(), null);
    ;
    if (objIdent && objIdent.object())
    {
        throw error("The form BLA-BLA is already open. It is not possible to open more than one BLA-BLA form",
                    "BLA-BLA");
    }
    infolog.globalCache().set(classstr(SomeClassResponsibleForLocking), curext(), new ObjectIdent(this));
}