Hi normamarshall,
You ask an interesting question: will the school that granted you the Grad Degree also be open to accepting you as a PhD candidate? The BEST source of information on this issue is the school itself. I recommend that you contact the admissions department directly (perhaps even schedule a meeting) and ask your questions. If you have any strong relationships with the staff (Professors, Administrators, etc.), then you might be able to take advantage of those relationships to help your application.
GMAT assassins aren't born, they're made,
Rich