Key problem

Hi,

I am having an issue. I had two keys for my skoda octavia 99 LX. Now when I try to open the car by using buttons on one key, It just blinks one red light and do nothing. I changed batteries but problem persists. On the other hand When i use other key it works perfectly.

Another issue is that, I can't use any key to open door manually using. Car horn start ringing. I can only use buttons on keys to unlock the door. Kindly can any one guide me where is the problem and how to fix it.

BR

Farooq Ahmad