Cannot get in car keys do not work when did 1 hour before on mercury cougar 1999?

Question

climbed in back of trunk and got in car when start car alarm goes off when open car's door from inside alarm goes off

Answer 1

Unhook the battery for 30 mins to reset default codes :)

Answer 2

push the key in all the way and then pull back just a hair,try to turn ,try different depths ,try pushing the key down or up a little
I don't know why but those keys to that car over time need to be held back a little.

Answer 3

Your locks are probably froze up. You can buy deicer at any store you spray it in the locks