window.onload = function() {

 document.getElementById('select_all').onclick = function() {

  var ipsum = document.getElementById('lorem_ipsum');

  // For IE
  if (document.selection) {

   var range = document.body.createTextRange();
   range.moveToElementText(ipsum);
   range.setEndPoint('EndToEnd', range);
   range.select();

  // For everything else
  } else {

   var range = document.createRange();
   range.setStartBefore(ipsum);
   range.setEndAfter(ipsum) ;
   (window.getSelection()).addRange(range);

  }

 }

}