help with Avatar uppload system

Aight, im developing a Avatar uppload system on my CMS and i just wanna know, is there some way to check the weight and height on the picture that is upploading? cuz i dont wanna have someone upploading a fuckin background image so it locks fuxxed upp when you display it :S Any help is appreciated :P

php.net/gd

Dooh!, now i remember :P, Thx so much Spyware :P

Okay, so i got the whole thing now, i need to use either image_info() or imagesize() but how do i use them :S, theres no specific usage in the php site :S any help appreciated :P