If your existing key is grey, then you'll need a "transponder" key, as in the link. If your existing key is black, then you won't need a transponder key. The transponder key will need to be programmed. If you have 2 keys already that work, you can program a third key yourself. If not, a trip to the dealer is necessary.
When programming the remote yourself, note the instructions in the owners manual carefully. You actually must program BOTH remotes at the same time, one right after the other, or only one will wind up working.
Check eBay for remotes and keys. This is what the correct remote looks like:
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

Try to get as much of that Vaseline as you can off the rubber boot. Vaseline is a petroleum based substance that will wind up degrading the rubber. Next time use soapy water.

 

Thanks Dcotter. I bought two of the following keyless remotes off of ebay. There was a lot to choose from but this seller seemed the most reputable.

eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

I'm confused regarding "black key vs gray key", When I bought the car it only had one plain old ignition key (not with a built in entry device) that was black in color. No keyless entry devices....Thanks

 

I just looked at the keys at the above link. The seller lists them as being for 2004 Chrysler vehicles. Teddysmith1952's car is a 2002. My car is a 2005 Sebring and I do need a second key. I don't want to hijack the thread but I am wondering, for myself and anyone else considering buying them, if these keys will work with vehicles that are newer/older than 2004?

 

Check with the seller. If the guy who sells the stuff on eBay misrepresents it, it's pretty easy to get your money back.

 

"Black or grey" refers to the part of the key you touch with your fingers when it's in the lock and you turn it. It's the plastic part. If yours is black, then you don't have the security (transponder) key. The grey key is a little thicker (still no buttons or anything on it) and would need to be programmed in order to work in the ignition to start the car successfully.

That remote you bought looks like the right one.

 

Follow-up:

Just got back from the local Chrysler dealer with the 2 keyless remotes I bought off of ebay. Programmed and work perfectly! It took the tech about 5 minutes (less time than to make up the invoice) and they only charged me $30. Thanks again for all the help.