1 function $(selector){ 2  return new O(document.getElementById(selector)); 3 } 4 function O(ele){ 5  this.ele=ele; 6 } 7 O.prototype.show=function(){ 8  this.ele.style.display=''; 9  return this;10 };11 O.prototype.hide=function(){12  this.ele.style.display='none';13  return this;14 };15 $('#id').show().hide();