Just above the textarea that you use to enter the message text there is usually a button bar with buttons to add text formatting like Bold and Italic.<br /> That toolbar may also have a button to turn a text link into a clickable hyperlink (look for a chain like button).<br /> You can select the text and click that button to turn the link into a clickable hyperlink.<br /> If you can't find the button then hover them all to check the tooltip of each.<br /> <br /> * Make Link - https://addons.mozilla.org/firefox/addon/142