asp的url编码和解码

<%
function urldecoding(vstrin)
'qiushuiwuhen(2002-6-19)
dim i,strreturn,strSpecial
strSpecial = "!""#$%&'()*+,/:;<=>?@[/]^`{|}~%"
strreturn = ""
for i = 1 to len(vstrin)
thischr = mid(vstrin,i,1)
if thischr="%" then
intasc=eval("&h"+mid(vstrin,i+1,2))
if instr(strSpecial,chr(intasc))>0 then
strreturn= strreturn & chr(intasc)
i=i+2
else
intasc=eval("&h"+mid(vstrin,i+1,2)+mid(vstrin,i+4,2))
strreturn= strreturn & chr(intasc)
i=i+5
end if
else
if thischr="+" then
strreturn= strreturn & " "
else
strreturn= strreturn & thischr
end if
end if
next
urldecoding = strreturn
end function

function urlencoding(vstrin)
dim i,strreturn,strSpecial
strSpecial = "!""#$%&'()*+,/:;<=>?@[/]^`{|}~%"
strreturn = ""
for i = 1 to len(vstrin)
thischr = mid(vstrin,i,1)
if abs(asc(thischr)) < &hff then
if thischr=" " then
strreturn = strreturn & "+"
elseif instr(strSpecial,thischr)>0 then
strreturn = strreturn & "%" & hex(asc(thischr))
else
strreturn = strreturn & thischr
end if
else
innercode = asc(thischr)
if innercode < 0 then
innercode = innercode + &h10000
end if
hight8 = (innercode and &hff00)/ &hff
low8 = innercode and &hff
strreturn = strreturn & "%" & hex(hight8) & "%" & hex(low8)
end if
next
urlencoding = strreturn
end function
%>