Sewing machine HELP!!?

I have a Singer merritt machine, and as I was sewing, the feed dogs seemed to have lowered. I think this because they're not pushing my material through. Also, as they seem to be down, the bobbin thread is not being threaded through the top thread. So when I insert the bobbin and turn the wheel to feed the bobbin thread through, nothing happens. HELP! Thanks (: I have looked all over my machine and can not find any lever that raises or lowers the feed dogs...