>Thanks Cetin
>
>The function is COMPRESS. The interface (in VB) is the following:
>
>Declare Function compress Lib "ZLIB.DLL" (ByVal compr As
> String, comprLen As Any, ByVal buf As String, ByVal buflen
> As Long) As Integer

Partial code from my own class :

PROCEDURE init
LOCAL lcPath
lcPath = ADDBS(JUSTPATH(this.ClassLibrary))
Declare integer compress in (lcPath+"zlib.dll") ;
	string @ dest, integer @ destLen, string @ src, integer srcLen
Declare integer compress2 in (lcPath+"zlib.dll") ;
	string @ dest, integer @ destLen, string @ src, integer srcLen, integer nLevel
Declare integer uncompress in (lcPath+"zlib.dll") ;
	string @ dest, integer @ destLen, string @ src, integer srcLen
ENDPROC

PROCEDURE destroy
CLEAR DLLS 'compress', 'uncompress'
ENDPROC


procedure CompressString
LPARAMETERS tcString
#define ZLIB_NOERROR 0
   this.nOriginalSize = Len(tcString)

   lnDestLen = CEILING(this.nOriginalSize * 1.02 + 12)
   lcBuffer = REPLICATE(CHR(0), lnDestLen)

   lnResult = compress2(@lcBuffer, @lnDestLen, @tcString, Len(tcString),9)

   If lnResult = ZLIB_NOERROR Then
      this.cCompressed = Left(lcBuffer, lnDestLen)
      this.nCompressedSize = lnDestLen
   ELSE
	  this.nCompressedSize = 0
   EndIf
   RETURN (lnResult = ZLIB_NOERROR)
EndProc

Cetin