iPhone/iPad hover function

The hover event (can be provided by css or javascript) is not supported in iPad/iPhone.

The workaround is use javascript: "onclick='javascript: f1();'". f1() is defined as:

function f1(o) {
  if ( navigator.userAgent.match(/iPhone/i) || 
       navigator.userAgent.match(/iPad/i) ) { 
    // do the hover work. for example:
    var x = document.getElementById('elemId');
    x.style.left = u.parentNode.offsetLeft + 'px'; // needed for positioning.
    x.style.visibility = 'visible';
  }
  return true;
}

Some sources say one can also use ontouchstart() and ontouchend(). But they didn't work in my situation.