I went out to go to work this morning and my shifter would move but nothing would happen. I thought maybe it just wasn't catching so I put it back it park and wiggled it around. When I put it back in reverse it went into gear with more of a jerk than usual. Anyway, on the way to work it shifted just fine. If I run it through the gears everything is just fine, until I put it in park. The gears disengage, I can rev it up and it goes nowhere. The problem is that it won't stop rolling. I mean I could push it all the way down the block if I wanted to, AND IT'S IT PARK! Help!! Any ideas, I'll check the fluid level when I get home.