Losing weight...NOT!

Well, I THOUGHT that not fitting into the dress I'd wanted to wear would give me the motivation to get up early and work out...for the past 2 mornings the alarm has gone off, and I've just laid there.  This morning HG asked me :I thought you were getting up?"....my reply...."My get up and go got up and went."  So I'm asking, how do you get motivated?  What works for you?