Try it this way, somehow it works fine in Firefox but not in Chrome, maybe a browser compatibility issue..
HTML -
<div class="selectme">Some text to highlight</div>
<div> Don't select this </div>
<div class="selectme">Select this text too.</div>
<br>
<p>Click me!</p>
Javascript-
function SelectText(element) {
var strongs = document.getElementsByClassName(element);
var s = window.getSelection();
if(s.rangeCount > 2) s.removeAllRanges();
for(var i = 0; i < strongs.length; i++) {
var range = document.createRange();
range.selectNode(strongs[i]);
s.addRange(range);
}
}
$(document).ready(function(){
$('p').click(function() {
myClass="selectme";
SelectText(myClass);
});
});
And here is a live JSfiddle example