问个escape的问题

Question

这个被转成的gb2312编码
<script language="vbscript">
function URLDecode(enStr)
dim deStr,strSpecial
dim c,i,v
  deStr=""
  strSpecial="!""#$%&'()*+,.-_/:;<=>?@[\]^`{|}~%"
  for i=1 to len(enStr)
    c=Mid(enStr,i,1)
    if c="%" then
      v=eval("&h"+Mid(enStr,i+1,2))
      if inStr(strSpecial,chr(v))>0 then
        deStr=deStr&chr(v)
        i=i+2
      else
        v=eval("&h"+Mid(enStr,i+1,2)+Mid(enStr,i+4,2))
        deStr=deStr&chr(v)
        i=i+5
      end if
    else
      if c="+" then
        deStr=deStr&" "
      else
        deStr=deStr&c
      end if
    end if
  next
  URLDecode=deStr
end function</script>
<script language=javascript>
alert(URLDecode("%BA%A3%D1%B2"))
</script>