How to spam on LFG automatically?

I'm trying to sell some stuff in game. I'm wondering if there's a command to spam automatically? Is there a command to do such? I get tired of typing and re typing the same thing after 20s or so. Most of the times, I forgot to type it on LFG... Can't keep up!

 

Push enter
push up key till you see your trade message
enter again.

Or Push "U" for macro.

Edit new macro.

Type /3 {Your trade message}

and put that macro somewhere on your hotbar and click it when you want to shout message again.

OR

Copy and paste.

 

Thanks a lot...