function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      oldonload();
      func();
    }
  }
}

function highlightRows(){
	if(!document.getElementsByTagName) return false;
	var table = document.getElementById("link");
  var rows = table.getElementsByTagName("tr");
	var currentClass;
	for(var i=0; i<rows.length; i++) {
		rows[i].onmouseover = function() {
			currentClass = this.className; 
			this.className += " hover";
		}
		rows[i].onmouseout = function() {
			this.className = currentClass;
		}
	}	
}

addLoadEvent(highlightRows);