1.里面随机取十个字符：
${__RandomString(10,里面取十个qwertyuiopasdfghjkl)}
2.随机取一个：
${__chooseRandom(102,101,103,201,203,11009,0,1,10208,10307,99000,Rand)} ;
3.随机从1~20中取一个：
${__Random(1,20)}
