给一个生成随机码的函数

Public Function MakeRndPass(ByVal passlen,ByVal passtype)
dim passFull,passNumber,passSpecial,passCharNumber,passChar,pass,passUpperCharNumber,passLowerCharNumber,passUpperChar,passLowerChar,ii,jj
passFull = " 1234567890!@#$%^&*()[];',./{}:?`~-=/_+|abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
passNumber = "1234567890"
passSpecial = " !@#$%^&*()[];',./{}:?`~-=/_+|"
passCharNumber = "abcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ"
passUpperCharNumber = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ"
passLowerCharNumber = "abcdefghijklmnopqrstuvwxyz1234567890"
passChar = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
passUpperChar = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
passLowerChar = "abcdefghijklmnopqrstuvwxyz"
select case lcase(trim(passType))
case "passfull"
pass = passFull
case "passnumber"
pass = passNumber
case "passspecial"
pass = passSpecial
case "passcharnumber"
pass = passCharNumber
case "passchar"
pass = passChar
case "passupperchar"
pass = passUpperChar
case "passlowerchar"
pass = passLowerChar
case "passuppercharnumber"
pass = passUpperCharNumber
case "passlowercharnumber"
pass = passLowerCharNumber
case else
pass = passlowercharnumber
end select
makeRndPass=""
for ii=1 to cint(passlen)
randomize
jj = int(rnd()*len(pass)+1)
makeRndPass = cstr(makeRndPass) & mid(pass,jj,1)
next
End Function