Remember when Jordin Sparks belted out last year’s winning number, “This Is My Now”? You probably thought you could’ve done waaay better. Well, time to put up. “American Idol” is once again giving aspiring songwriters a chance to pen an instant-hit single, broadcast to a worldwide audience of MILLIONS. MILLIONS! Submit entries from now ’til March 31 at AmericanIdol.com, and please stop sending US your demos. The online-voting phase begins April 10, and the winning song will be performed during the “Idol” season-seven finale May 20.