String.prototype.trim=function(){   
  return   this.replace(/(^\s*)|(\s*$)/g,"");   
  }
String.prototype.IsEmail=function(){   
    var reg = /^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+((\.[a-zA-Z0-9_-]{2,3}){1,2})$/;
       return reg.test(this.trim());
       
         }