cannot change mode

I started working on this last night but i must have accidentaly pressed something and saved it so i am now stuck in object mode. I can change the mode in any other blender file this is the only one which has been affected by my foolishness.

http://img160.imageshack.us/img160/4032/blenderproblemky7.jpg
how do i fix it?

Nice model. I’m surprised you got so far without running into the “can’t edit” problem earlier. Here’s the deal: no objects in your file are selected. Blender can’t edit until you tell it what you want to work on. So, select the object, and then edit mode will work.

Your other work must have been saved either when in edit mode (which reopens with the object automatically selected) or in object mode with the object still selected. Chances are this one you were in object mode and typed “a” to deselect all objects just before you saved it, and it reopened in the same state.

The name of the object selected is in your lower right-hand corner of your 3D view, preceeded by the number of objects selected.

Also, if you select the camera, there is no edit mode for the camera…so if you think you have that mean-nasty-rifle-meant-to-kill-others object selected for editing, but you don’t, you wont find your expected edit mode either.

So, to directly answer your question, right click on the outline of the rifle object.

ah the problem was so simple… oh and my model there is not all it seems in that screen shot. It’s basicaly just a picture of the rifle im modeling with a 3d outline but hopefully i’ll be able to make it the full thing…

For something like this rifle, you might want to try building it part by part.
I’d go with box modeling: extrude a long rectangle for the stock, a cylinder for the barrel, and another cylinder for the scope. Make cuts everywhere the profile changes, and move verts around until it looks like the rifle.