asp.net随机产生6位数密码怎么写啊？

asp.net随机产生6位数密码怎么写啊？

System.Random a=new Random(System.DateTime.Now.Millisecond);
int RandKey =a.Next(100000,999999);

生成随机密码：public static string MakePassword(string pwdchars, int pwdlen)
{
string tmpstr = "";
int iRandNum;
Random rnd = new Random();
for (int i = 0; i {
iRandNum = rnd.Next(pwdchars.Length);
tmpstr += pwdchars[iRandNum];
}
return tmpstr;
}
load中：
string randomchars ="abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
Response.Write(MakePassword(randomchars, 50));