Is it normal for my friend to obsess over a guy like this?

My friend has known this guy for 2 years. they have been kind of infatuated with each other off and on since. They've been bf/gf a few times. Now in these past few weeks she has been obsessed with him. He is all she thinks about basically. In the shower, getting ready, posting a bulletin on myspace, going to work, everything and everywhere. She has dreams about him. Literally he's taking over her life. He used to be obsessed with her like this, but not so much anymore. And she is just sooo obsessed. Everything literally everything is about him. Is this normal for her, she is 15. she thinks she's in love with him, but they haven't even hung out together in person for over a year, just over the phone and myspace. She waits for him to call, and when he doesn't pick up or hits ignore she assumes e is talking to this other girl that goes to his school. they don't go to the schoo anymore btw

Is it normal for my friend to obsess over a guy like this?

She's 15 years old and has a really bad crush on a guy. Fortunately he's not reciprocating or else she'd probably end up even worse hurt after he'd taken advantage of her.

She'll realize he doesn't care, then she'll cry about it, and feel bad for a while, until she falls for some other guy.