Anti Theft in 98

I have a 98 silverado and some ahole broke in yesterday and tried to steal it. My model has a device that came with the truck that when the ingnition is messed with all power is shut off and the now i can't get my key in the barrel to turn it over. Can some one fill in the gaps and explain this more to me and also the cost of replacement? thanks

Go to the C/K forum, this one is for 1999 NEW body. Sorry, Good Luck.