>>BUT as always there's an issue, this code does not work with firefox,

 

var oRange = oSelection.createRange();

 

This line will not work with firefox.

 

  if (document.selection) { // IE 
        var rng = document.selection.createRange(); 
    } 
    else { //Firefox 
        var sel = document.getSelection(); 
        var rng = window.getSelection().getRangeAt(0); 
    }