1) Go to the address bar at the top of the page
2) RIGHT CLICK on URL (web address) it will be highlighted
3) Click on COPY in the little window that opens
4) Go to 3A reply place your cursor on the place you want to post the URL
5) RIGHT CLICK and choose PASTE from the little window
The address will appear as it does at the top of the webpage but although very long it will be automatically shortened (parsed?) once you post