A decent first try but there is a lot of things that is off with it.

The first thing is that the the body doesn't move a single bit, I'm sure you're aware of that though. When the legs on the ground are further away from the body it should be down, when they are under the body it should be up. Head and tail should be dragged up and down with the body with a bit of delay.

The legs need to have a consistent movement, meaning that when they are on the ground and in the air, they move in the same speed all the time. If you look at the three first frames you'll notice that the front front leg is in the same position. It means that the leg on frame two and three it slides forward on the ground and only in frame four it moves backwards. What you want is it to consistently move backwards on the ground.

I edited this one a bit, it is still a bit jerky but I think you get the idea. http://www.mediafire.com/view/?sfmaayvjso276d2

I forgot, here's a tutorial I made for walking animations, it is for a two legged creature but it is still helpful. http://legendofkrystal.com/forum/viewtopic.php?f=29&t=2533

Thank you very much for the info. Sorry it took me a while to reply, I have been busy lately. I'll take this into consideration next time I make a walk cycle!

I wondered if you'd reply but then I forgot about it. You're welcome. I like to help other animators, especially new animators since they need help the most.

If and when you make another animation, show it to me first if you'd like my thoughts on it. I always got time, most of the time...

I will, thank you!