trim() function doesn't work in IE8?

Question

Whenever I use the trim() function on a string, it works fine with Chrome and Firefox but I get an error in IE8 saying :

Object doesn\'t

Answer 1

Since, I was using jQuery, with the help of @nemo and @karesh-a I came up with:

if(typeof String.prototype.trim !== 'function') {
     String.prototype.trim = function(){
        return jQuery.trim( this );
    }
}