Take your mouse pointer to the beginning of the text you want to copy and hold down your left mouse button (that's the one you normally use). Then drag the mouse pointer to the end of the text you want to copy. This highlights it. Let go of your left mouse button. While holding your mouse pointer over some of the highlighted text you will need to click your right mouse button (that's the one you don't normally use) and a menu will pop up. Go down until "copy" is highlighted then click on it.