Playing all songs on iTunes

Was wondering how you play ALL songs on iTunes. I go into my main library and it used to play all the songs. Now it stops after each one. I looked in help and all, but to no avail. Sidenote, not being able to use a free email to register is about the dumbest s#$t Ive ever heard. Thanks for any help!

Make sure all the songs have a check mark next to them. If they are all unchecked, then it will only play the one you select. To check them all, click on one song and hit Option+A, then right+click on the blue area and choose Check Selection