How do i activate a script when a linedef is used?

Just now, StillChillBoi said:

 

script 1 OPEN { }
 

There you go.

Make it a void script.

43 minutes ago, StillChillBoi said:

I wanna make a message appear when the player uses a linedef, it works, but the message also comes up when the level starts which is not what i want

Since we cannot read your mind or deduce what you have done on your computer, it is always a good practice to give lots of information, like uploading the text of your script.

What type of script do you use?

https://zdoom.org/wiki/Script_types

Well the script looks like this:

#include "zcommon.acs"

script 1 OPEN {
    Print(s:"You aint gonna walk out of here and let the demons spread hell into the building! Plus, the lift is broken!");
}

Also i'm using doom 2 UDMF format

thx