Mercedes: 1997 e420 mercedes benz will not start after alarm, hood latch, heat radio

Question
Hello.
My dad was sitting in his 1997 e420 Mercedes with the doors closed.  He hit the remote button on accident and it locked the doors.  He then lifted up on the unlock button and opened the door.  The alarm started going off.  After, he tried to start the car, and it starts for a second and then shuts off.  Can you please let us know how to reset his alarm ?

Answer
Ron
Turn off all accessories heat, radio AC etc. Release the hood latch. Exit the vehicle and using the Key, lock the doors. Remember the direction to lock. Wait until all locks have cycled down before removing the key.
Open the hood. Remove the battery terminals (-) then (+) in that order. Clean the battery post and terminals wait 10 minutes. Reinstall the terminals in reverse order. Close the hood firmly.
Insert the drive door key and "remembering the correct direction for unlocking the door" unlock the vehicle and wait until all locks have cycled open before removing the or trying to open the door.
This process should reset the vehicle computer including the security alarm. Good Luck
Rob