Dial *#307# and hit call
The iPhone will now start to ring itself, once it start to ring you have to erase *#307# by using the backslash button on your iphone and then type 0 and then CALL, the iphone will ring again and this time hit "Answer" then hit "Hold", the Phone will start to ring itself again, this time click "Decline".
Now on the screen you should be able to get to the contacts menu down the bottom, tap "Contacts" and then add a contact. Use the following instructions:
Add the Name "Testing" and tap save
Tap "Add URL" and type "prefs://1F" then tap save
Tap "Add URL" again and type "jailbreak.unlockthatiphone.com" then tap save
When this is done, tap "Save" again and it will take you to the contact page displaying the name "Test" and the two URLs you just added. Tap the "prefs://1F" URL and it will open the iPhone Settings page.
Tap "General" and Then "Auto-Lock", set it to "Never".
Go back to the settings page From here, tap WiFi and Add your WiFi network and make sure you are connected to it