I can't get past the lock screen on my iphone 3gs and i don't have a passcode?

My Phone is already Jailbroken

Added (1). I can't go into emergency call because I don't have a passcode

You can by-pass iPhone, iPad or iPod's security by following the steps given below:
1. Make sure your device is locked. 2. Activate the screen.
3. Enter "Emergency Call".
4. Tap on the "ICE" button found on the bottom left.
5. Press and hold the home button for a few seconds and then release it.
6. The phone's home screen will be displayed.
7. While the home screen is visible click on any app or widget and it will launch without the password