help with extruding basic circle

[aebstract]

Hello,
I am new to solidworks, and I have a training dvd that I am going along with, however I am running in to a small problem that I can't seem to figure out. I am drawing a circle and then going to the 'extruded boss/base' tool to raise it up. Whenever I click the check mark to submit the extrusion it says "The direction of extrusion must be specified for 3D sketch". I've had this come up a few times and a few times it hasn't. I noticed that when I get the error, it's not showing me the arrow that I can drag to change extrusion amount, how come it's not coming up sometimes but others it is? This is on solidworks 2008 premium.
Thanks

[SolidMartin]

Check this tutorial: Extrude - Tutorial for beginners, may it would be of some help to you.
Cheers!

[seon]

The problem is that you have done a 3D sketch instead of a 2D sketch.