I made my item send a message to the player to check the mode the item is in, but the message always displays twice.

 

The chat to the player is on line 20 & 21.

 

http://pastebin.com/zHEV8up6

The reason you are getting two messages is because it's sending the chat to both the server side and the client side. You need to make sure it only sends it to one side (server side in most cases...).

 

Anywhere where it sends a chat to the player, surround the statement (or multiple statements) with this statement:

 

if(!world.isRemote){}