1996 Winstar GL - Alarm Went Off - Need Help

[mdirfan]

Need help !!!

My van's alarm went off suddenly and I am not able to start the vehicle
(I don't have the key pad and did not know that my van has an alarm. The person who sold the van to me almost a year ago did not tell me about the alarm and did not give me the key pad)

Tried locking and unlocking with the key does not help. Alarm stops after a while and if i try opening the door or do any thing it goes off again. Lights blink and I can hear a tick tick sound. I have disconnected the wire that is connected to the alarm

What do I do now ?
How do I reset the alarm with out the key pad?
Is it possible to get the same system reprogrammed with a key pad? where can I get in done in the Detroit area and how much will it cost?

PLEASE PROVIDE ME WITH INSTRUCTIONS ON SOLVING THIS PROBLEM AND I THANK YOU IN ADVANCE