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

 1 var createUUID = (function (uuidRegEx, uuidReplacer) {
 2      return function () {
 3          return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(uuidRegEx, uuidReplacer).toUpperCase();
 4      };
 5  })(/[xy]/g, function (c) {
 6      var r = Math.random() * 16 | 0,
 7          v = c == "x" ? r : (r & 3 | 8);
 8      return v.toString(16);
 9  });
10  alert(createUUID());