In Safari (Apple's default browser) I used to lose my way (and lines and lines of text) trying to back-track to the "Reply to Thread" box by means of the back-arrow, because Safari used the same page for successive actions (I know you could generate a new page before doing anything else, but in the heat of the moment this hardly ever(never) happens).

In Firefox (free downloads available for both Macs and PCs), setting up a new tab allows the "Reply to Thread" box to stay in its own tab while you seek the page you want to link to. When you have copied the URL, return to the reply box tab. New tabs seem to be generated automatically thereafter by the link-maker, link test etc, so the reply box tab is always there to go back to.

Ross