String.prototype.trim=function(){return this.replace(/\s/g,"")};String.prototype.lrtrim=function(){return this.replace(/(^\s*)|(\s*$)/g,"")};String.prototype.ltrim=function(){return this.replace(/(^\s*)/g,"")};String.prototype.rtrim=function(){return this.replace(/(\s*$)/g,"")};String.prototype.len=function(){return this.trim().length};String.prototype.isnull=function(){var $=this;return $.replace(/\s/g,"")==""};String.prototype.ismath=function(){if(this=="")return false;if(/^(\-?)(\d+)$/.test(this))return true;else return false};var $=function($){return document.getElementById($)};String.prototype.getQuery=function(A){var _=new RegExp("(^|&)"+A+"=([^&]*)(&|$)"),$=this.substr(this.indexOf("?")+1).match(_);if($!=null)return unescape($[2]);return null}