tmux script corrected

tmux_ssh

 #!/bin/sh
 #
-SESSION=$(tmux display-message -p '#S' 2> /dev/null)
+SESSION=$(tmux ls -F "#{session_name}")
+
+echo $NEW
 
 if [ "$SESSION" = "" ]; then
 	tmux attach-session -t default_ssh || tmux new-session -s default_ssh
+else
+	echo tmux-session \"$SESSION\" already running.
 fi