There isn't a clip trimmer option on my iMovie.

Ive been trying to edit a short film i shot on my iphone in iMovie, and i found this http://support.apple.com/kb/PH2206 suggesting how to trim a clip on iMovie. I am trying to use the clip trimmer option that you get by clicking on the action pop up menu. However, when i click the action pop up menu I dont get clip trimmer as an option on there...i only get the options; Clip adjustments, Video adjustments, Audio adjustments, and Cropping & rotation.

Is there anything i need to do to get this 'clip trimmer' option on the action pop up menu. Or does anyone know why it might not be on there?

Thanks.