js array duplicates

array duplicates

Array.prototype.unique = function () {
    var r = new Array();
    o:for(var i = 0, n = this.length; i < n; i++)
    {
    	for(var x = 0, y = r.length; x < y; x++)
    	{
    		if(r[x]==this[i])
    		{
                alert('this is a DUPE!');
    			continue o;
    		}
    	}
    	r[r.length] = this[i];
    }
    return r;
}

var arr = [1,2,2,3,3,4,5,6,2,3,7,8,5,9];
var unique = arr.unique();
alert(unique);