Change image src on img:hover

function hover(element) {
    element.setAttribute('src', 'http://dummyimage.com/100x100/eb00eb/fff');
}
function unhover(element) {
    element.setAttribute('src', 'http://dummyimage.com/100x100/000/fff');
}
function unhover(element) {
if(navigator.userAgent=='prog'){
  $(element).children().attr('src','/style/img/Print.png');
   }
}
function hover(element) {
if(navigator.userAgent=='prog'){
  $(element).children().attr('src','/style/img/Print-h.png');
   }
}

<img id="my-img" src="http://dummyimage.com/100x100/000/fff" onmouseover="hover(this);" onmouseout="unhover(this);" />