很实用的js限制不让输入其他字符，只让输入数字和 js生成UUID

onkeyup="this.value=this.value.replace(/\D/g,'')"

js生产UUID

 var createUUID = (function (uuidRegEx, uuidReplacer) {
      return function () {
          return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(uuidRegEx, uuidReplacer).toUpperCase();
      };
  })(/[xy]/g, function (c) {
      var r = Math.random() * 16 | 0,
          v = c == "x" ? r : (r & 3 | 8);
      return v.toString(16);
  });
  alert(createUUID());