String.prototype.trim = function() { return this.replace(/^\s+|\s+$/, ''); };
String.prototype.validateEmail = function() { return this.trim().match(/^([a-zA-Z0-9_])+([a-zA-Z0-9_\.])*\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/); }