new mobo ?'s

[yammahoppy]

i currently have a pII266 running on an old asus lx (pl297)chipset mobo. i want to step up to a more current configuration (bc chipset). i am looking at the asus p3b-f. the reason i am looking at this is it supposedly will work w/ my pII266, and also supports the pIII (want to get the board now and get the new cpu later). the main question i have is, if my case is an atx mid tower will the asus mobo fit in it? all of my other components are working fine.
any help i might will be greatly appreciated.
thanks