Forget the phone lock code. i forgotten the code for my N73 cell phone,when i switch on the

Question

i forgotten the code for my N73 cell phone,when i switch on the phone,i have to enter the code to activate my phone,now i have forgotten the code and how do i unlock my phone? the handphone shop is asking for $70 to refresh the phone and unlock it and it takes 3days. is there any other way that i can get to unlock the phone?I don't know what is my unlocking code for my n70....Can somebody help me whit a trick to unlock it?Thanks!