Handles Buttons

Howdy, I am attempting to use the Handles.Button function for OnSceneGui, but I get an error on the DrawCapFunction parameter. I am coding in C# and am wondering if anyone else has used this function before and can shed some light on this?

 

what's the error? can you paste in the exact text?

 

Well, if I copythe example in the unity docs(http://docs.unity3d.com/ScriptReference/Handles.Button.html) I still get an error, which is odd, although the example is only in Javascript so that might be why