Tied in Knots

To work this puzzle, you will need a friend and two pieces of string, each 80 centimeters long. Use one length of string to tie your friend’s wrists together loosely. Loop the second length of string over the first length, and then loosely tie your own wrists together with the second length. Can you and your friend untangle yourselves without breaking or untying the string or slipping the tied loops off your wrists?