jQuery.fn.selectText = function(){
   var doc = document;
   var element = this[0];
   console.log(this, element);
   if (doc.body.createTextRange) {
       var range = document.body.createTextRange();
       range.moveToElementText(element);
       range.select();
   } else if (window.getSelection) {
       var selection = window.getSelection();        
       var range = document.createRange();
       range.selectNodeContents(element);
       selection.removeAllRanges();
       selection.addRange(range);
   }
};

$('body').selectText();