And if you're paying by the minute, you can just shrink (rather than close) your browser on the Mudcat thread you wish to respond to, go offline, compose your answer in the box, go back online and hit the submit message button.
Another nifty trick I learned here a while back is to RIGHT click on the Forum, and open the thread I want in a separate window. Then you can reduce several if you have room, and even READ them offline, as well as respond.
Blessings,
Barbara