String.prototype.trim = function(){return this.replace(/(^[ |　]*)|([ |　]*$)/g, "");}
function $(s){return document.getElementById(s);}
function swap(s,a,b,c){$(s)[a]=$(s)[a]==b?c:b;}
function hide(s){$(s).style.display=$(s).style.display=="none"?"":"none";}