Xcode 4.1 'Run' won't work..

I have a very simple program coded, and it builds successfully, but since even there wasn't any code, it would build but not run. Also, the run option in the Product menu is grayed out..
here is a picture of the menu.
img.ly/8Nt4
also, when i click build and run, the stop button appears for a second and then immediately grays out, and the program doesn't load each time before the build succeeded message appears..