There are two things you need to set up first:
We set the currElem global variable because you can't pass variables to a method using an interval or timer. Then, once the is set, it's just a matter of incrementing the left amount (pushing the element to the right) until it's greater than or equal to the total amount you want it to move. You can then increase or decrease the top to get a diagonal and many other things. Varying the timeout time (in this case 10 milliseconds) and the interval distance will make the movement clunkier or smoother, depending on what you're looking for.