Whats that song that has the lyrics "waiting, on the line."?

The "waiting, on the line" line is the only part i remember and its sung in kinda a doowop style with a doowop style b riff. It's either 2007-2008 cuz of the video quality and i saw it on much music megahits a bunch a year ago. The video is of a black girl (the singer) with an afro, trying to get with this other black guy who looks nerdy at first but she changes him. anybody know wut song im talking about?