please can anyone tell me how to hard reset a nokia e72?

[vinss]

i turned off the phone then turnd it back on then it was askin for the auto lock code, i put in the code which i chnged from 12345 to something else. nw it's nt working?please help me, i hven't been able to use my phone for a week.if my parents find out about this i'm screwed..:'(