Blender 2.53 Viewport HELP!

I just downloaded the Blender 2.53 BETA, and I can’t figure out how to rotate view in the viewport. It’s not ALT+Click+move mouse, it’s something I can’t figure out. and I also can’t find it in the preferences for changing hot keys. Please, someone help me!

If you’re not using the middle mouse button to rotate, go to the User Preferences window and in the Input tab select ‘Emulate 3 Button Mouse’. Then save as default