[psy_wombats]

That doesn't look too bad. Two main things I notice from a cursory glance:

-You're using the assignment operator ( = ) in your if statements. Use the double equals ( == ) if you want to test equivalency. And the eqivalency things are in the assignments. You just need to double the equals where you have one and halve it where you have two right now. (I know this error, that's the first C mistake I ever made)

-You don't need the extra else if. You could probably use just the else, as the if will always be true. Not a necesity, but just a style thing I noticed.

Are you having any specific problems, or just looking for a first review of the code?