How do i unlock my sidekick slide

from the keyguard lock go to emergency calls.
after that press the:

1. menu key (top left hand corner)
2. shift
3. q

NOTE : Procedure will only allow you to Open your mobile features & texting/calling to anyone , but when you recieve a text , only number is shown (not the contact name IN SOME CASES) , also , this procedure don't work with some networks . When you reset your device , you have redo this procedure . Just take 30 Seconds .

You can use any network on Sidekick Slide now .
Steps to follow are very simple :
1) Insert your At&T (or other) sim card .
2) When it ask for the Special Code , simply Cancel it (press it x2) & move to Main screen .
3) Go To
- Menu
- Settings
- SIM Center
4) Now click Change SIM PIN & insert OLD/NEW SIM PIN
4a) If you get UNLOCK SIM , then click on it & put any code (i.e. 1122 , 0000)
5) No when it say "Waiting For Activation" , press Menu+L
6) Now Go To
- Menu
- Settings
- Network Options
7) Now Simply Select Scan & Select Manually
8) Select you network (At&T or any other) , Let your phone work properly .

What yugiocruz said