Can anyone Help me with this Formula?

I have been working on a spreadsheet in OpenOffice.org Calc and MS Excel for my GCSE coursework.

The forumla I need to make uses =IF to produce a result depending on the input.

=IF(C17="Bike",3,IF(C17="Run",3,IF(C17="Rollerblade",3,IF(C17="Walk",2,0))))

The cell next to it (C17) will contain a method of travel (e.g. Walk, run), and the cell with this formula needs to display a number (0, 1, 2 or 3) depending on the input.

I was wondering why my formula isn't working, and is there a way to go =IF and then put 2 logical tests in.

Thanks in advance.