Element.prototype.hide=function(){this.style.display='none';return this;}
Element.prototype.show=function(){this.style.display='';return this;}
Element.prototype.append=function(content){this.innerHTML+=content;return this;}
Element.prototype.prepend=function(content){this.innerHTML=content+this.innerHTML;return this;}
Element.prototype.setHTML=function(content){this.innerHTML=content;return this;}
function $F(elementId){return $(elementId).value;}