If the cord comes out:  Look at the hem/sleeve at the top of your Ursack. Notice there are two pairs of eyelets. One pair (A) is open only to the inside, the other pair (B) goes completely through the hem/sleeve. You can see through B, but not A. Thread cord through one of the A eyelets and pass it around through the hem/sleeve until it emerges from the other A eyelet. Cross the cords and push one end of each through the B eyelets.