转换html代码子程序

  function htmlencode(str)
    on error resume next
    dim result
    dim l
    if isnull(str) then
       htmlencode=""
       exit function
    end if

    l=len(str)
    result=""
dim i
for i = 1 to l
    select case mid(str,i,1)
           case "<"
                result=result+"&lt;"
           case ">"
                result=result+"&gt;"
           case chr(34)
                result=result+"&quot;"
           case "&"
                result=result+"&amp;"
           case chr(13)
                result=result+"<br>"
           case chr(9)
                result=result+"&nbsp;&nbsp;&nbsp;&nbsp;"
           case chr(32)            
                'result=result+"&nbsp;"
                if i+1<=l and i-1>0 then
                   if mid(str,i+1,1)=chr(32) or mid(str,i+1,1)=chr(9) or mid(str,i-1,1)=chr(32) or mid(str,i-1,1)=chr(9)  then                       
                      result=result+"&nbsp;"
                   else
                      result=result+" "
                   end if
                else
                   result=result+"&nbsp;"                     
                end if
           case else
                result=result+mid(str,i,1)
         end select
       next
       if err.number<>0 then err.clear
       htmlencode=result
   end function