In Edit  ribbon you have Order  option. Order "To Front"  will put your element the last on the page and it will be on top of every other element. Order "To Back"  will move your element to first position witch will move your element under every other element. Order "Step Up"  will move your element one position down in the "List of page elements" while order "Step Down"  will move your element one position up.
Note: Please remember that in the list of Page Content the elements on the buttom are the last ones added so they will be on top of the previous added elements.