Help! Security alarm going off

I replaced the battery in my 2001 Sephia. Now when I open the door the horn beeps and the exterior/interior lights flash on/off. I tried locking/unlocking the door before opening and actually cranking the car while the alarm is sounding, but it still keeps going off. It will eventually shut up only to come back if I continue to drive. Any help?

When you disconnected the battery, you reset the alarm. Find the owners manual. Reprogram the remote control. There is also a a setting that will cause the alarm to activate 3 seconds after closing the door (by default), change this to "don't auto-arm".

If all else fails. Open the car door, turn the ingition to "ON" then press or switch the toggle button.

This will put the alarm in Valet mode, and bypass it all together.