validate datetime in javascript

gistfile1

 //校验日期

 function isdate(object) {
     var s = document.getElementById(object.id).value;
     var pattern = /^((\d{2}(([02468][048])|([13579][26]))[\-\/\s]?((((0?[13578])|(1[02]))[\-\/\s]?((0?[1-9])|([1-2][0-9])|(3[01])))|(((0?[469])|(11))[\-\/\s]?((0?[1-9])|([1-2][0-9])|(30)))|(0?2[\-\/\s]?((0?[1-9])|([1-2][0-9])))))|(\d{2}(([02468][1235679])|([13579][01345789]))[\-\/\s]?((((0?[13578])|(1[02]))[\-\/\s]?((0?[1-9])|([1-2][0-9])|(3[01])))|(((0?[469])|(11))[\-\/\s]?((0?[1-9])|([1-2][0-9])|(30)))|(0?2[\-\/\s]?((0?[1-9])|(1[0-9])|(2[0-8]))))))(\s(((0?[0-9])|([1-2][0-3]))\:([0-5]?[0-9])((\s)|(\:([0-5]?[0-9])))))?$/;
     if (s != "") {
         if (!pattern.exec(s)) {
             alert('请输入正确的日期');
             object.value = "";
             object.focus();
         }
     }
 }