Method #1. Hold down the left mouse button, and drag it across the text to highlight it.
Then press the 'Ctrl' key and the 'C' key on your keyboard at the same time.
( To paste it to your web document, press the 'Ctrl' key and the 'V' key on your keyboard at the same time. )

Method #2. Hold down the left mouse button, and drag it across the text to highlight it.
Then 'right click' the highlighted text and then click 'Copy' from the menu that pops up.
( To paste it to your document, 'right click' on the web document you want to paste the code in,
and then click 'Paste' from the menu that pops up. )