hide() makes an image disappear, show() makes it reappear. To read a player's chat you would do
if (player.chat == "stuffHere"), so in your case:
PHP Code:
function onPlayerChats() {
if (player.chat == "/on") {
//Stuff
} else if (player.chat == "/off") {
//More Stuff
}
}
But if you're doing it in the offline editor then you won't be able to use GS2. Either way, you might have to play with it a bit so that it doesn't just hide for you but it hides for everyone else as well. There are block-type stuff posted around this section of the forums that already does similar things to what you want, just use the search function and search for hide() or dontBlock()/blockAgain() since it's similar concepts.