If a program stops responding for a long time, and it doesn't look like it's coming back, you can, fortunately, solve the problem without resorting to restarting the computer or other such drastic measures.
You will probably notice that the cursor changes into a multicolored pinwheel when you hover it over windows for the frozen program (This pin wheel looks like a spinning beach ball). If not, the program is probably not truly frozen.
There are three ways to force-quit a program. The first is to press ⌘-Option-Escape or select Force Quit from the Apple menu in the upper-left hand corner. This will bring up a menu of programs that can be force-quit. A hung program will be highlighted in red and marked with (Not Responding).
First:

Comments