I need help. Fastenening feature is grayed-out (trying to add a vent). I'm working as a student in the beginners guide to solidworks 2013 level II book.  My Insert drop-down is completely different than the example in the book but when I add the command from the command search it's grey-out. 

Any help would be greatly appreciated.  I can be reached here or amenrahkay@gmail.com

thanks!!