1. Go to their Xatspace. To do this, type "Xatspace.com/" into your URL bar and add their regname after the forward slash. For example, because my regname is "Proletariat", the URL for my Xatspace is "Xatspace.com/Proletariat".
2. Right-click anywhere on the page and select "View page source". If the "View page source" option isn't available to you, either switch to Firefox or Chrome or consult Google to find out how you obtain a page's HTML source code using your browser.
3. On the source page, press the Ctrl key and then the F key (Windows) or the Command key and then the F key (Mac) to bring up the search function. Type the user's regname into the search bar and press the Enter key twice. It should bring you to a line of code that looks like this:
As you can see, the user's ID is displayed right before their regname. You may highlight it with your mouse and press Ctrl + c to copy it to your clipboard.
4. If you want to add this person as a friend, visit any chat and type "/fID", replacing "ID" with the ID that you obtained from the last step. For example, if you wanted to add the user with the ID 1234, you would type /f1234 (and press enter).