Car Alarms: remote, security features, alarms

Question
we changed the battery in the remote now it will not work at all  so we can not get in the car and of course we can not start the car either we are on foot help

Answer
Typically most aftermarket alarms will have a way to manually override them.  Take a look under the driver's side dash of the vehicle and try to find a small switch.  With most alarms if you turn the ignition on and flip the switch it will disengage the security features of the alarm.  If you can post the exact make and model of the alarm I will see what I can do about locating an installation manual for your system which would shed more light on how to troubleshoot the problems you are having.