Potty Training

So lately potty training with James has fizzled out.  He started off with a bang a few months back when we bought his froggy potty.  He would sit on it all the time.  Then he plain out refused to go near it.  I tried the big potty and he liked that for a couple of months.  Now nothing until today.  What happened?  I ran out of diapers!  I remember using the last one from the diaper bag last night before jammy time.  When I went to change his diaper this morning, no diapers!  What is a mother to do?  Go to the store immediately right?  No, desperate times call for desperate measures...  The conversation went a little something like this...  I say, "James, we have no more diapers."  "No more?, " he replies.  "No more diapers honey.  Mommy needs you to go pee pee on the potty. Can you go pee pee on the potty for mommy?"  "Mmm-hmm."  Okay right.  So it's been 5 hours and he's sat on the potty three times already!  Fingers crossed!