Talk To Me @ - the book about friendship

When four girls, Stephiane, Olivia, Colleen, and London, enter high school at Silver Lake High School. They talk about secrets, social life, and school life. They're all so close until Colleen suddenly becomes very secretive. Will they become friends again or will Colleen not be their friend anymore? And, will they keep their friendship through-out the rollercoaster rides of high school?