IsChannelOpen

Function:

 * boolean isChannelOpen(channel)

Parameters:

 * channel - name of a channel in Tibia chat.

Return value:

 * This function return an boolean indicating if chat with given name is open or not. Returns true if open, false if closed.

Description:

 * This function checks, if chat with given name is open. Example names of the chat can be for example "NPCs", "Advertisment", names of players (private messages channel), etc.