Deepsea problems, again

I was using deep sea today and im wondering how to make switches and stuff like that. i want to make some traps where you step on a certain tile and a door opens. and what do the WR and SR things mean?

WR is walkover repeatable (so you can trigger the line multiple times), likewise SR is switch repeatable. Walkover would be lines you trigger by walking over them (duh) such as teleporters, switches are, uh, switches

W is walk over a line
w1 is only once; wr is an number of times.
S is switch.
for more help:
http://www.doomworld.com/sda/x3.htm
or read the DeepSea help.
good luck.

Then there are the G1 and GR switches. The G1 means the switch has to be shot, but it's only triggered once. The GR is triggered multiple times.

Thanks for the help everyone! now i can make levels that are actually fun. instead of just walking around looking for keys.