See below some functions declarations for Visual Basic. Frequently Asked Question: Q: Each time I use the compress function I get the -5 error (not enough room in the output buffer). A: Make sure that the length of the compressed buffer is passed by reference ("as any"), not by value ("as long"). Also check that before the call of compress this length is equal to the total size of the compressed buffer and not zero. From: "Jon Caruana" Subject: Re: How to port zlib declares to vb? Date: Mon, 28 Oct 1996 18:33:03 -0600 Got the answer! (I haven't had time to check this but it's what I got, and looks correct): He has the following routines working: compress uncompress gzopen gzwrite gzread gzclose Declares follow: (Quoted from Carlos Rios , in Vb4 form) #If Win16 Then 'Use Win16 calls. Declare Function compress Lib "ZLIB.DLL" (ByVal compr As String, comprLen As Any, ByVal buf As String, ByVal buflen As Long) As Integer Declare Function uncompress Lib "ZLIB.DLL" (ByVal uncompr As String, uncomprLen As Any, ByVal compr As String, ByVal lcompr As Long) As Integer Declare Function gzopen Lib "ZLIB.DLL" (ByVal filePath As String, ByVal mode As String) As Long Declare Function gzread Lib "ZLIB.DLL" (ByVal file As Long, ByVal uncompr As String, ByVal uncomprLen As Integer) As Integer Declare Function gzwrite Lib "ZLIB.DLL" (ByVal file As Long, ByVal uncompr As String, ByVal uncomprLen As Integer) As Integer Declare Function gzclose Lib "ZLIB.DLL" (ByVal file As Long) As Integer #Else Declare Function compress Lib "ZLIB32.DLL" (ByVal compr As String, comprLen As Any, ByVal buf As String, ByVal buflen As Long) As Integer Declare Function uncompress Lib "ZLIB32.DLL" (ByVal uncompr As String, uncomprLen As Any, ByVal compr As String, ByVal lcompr As Long) As Long Declare Function gzopen Lib "ZLIB32.DLL" (ByVal file As String, ByVal mode As String) As Long Declare Function gzread Lib "ZLIB32.DLL" (ByVal file As Long, ByVal uncompr As String, ByVal uncomprLen As Long) As Long Declare Function gzwrite Lib "ZLIB32.DLL" (ByVal file As Long, ByVal uncompr As String, ByVal uncomprLen As Long) As Long Declare Function gzclose Lib "ZLIB32.DLL" (ByVal file As Long) As Long #End If -Jon Caruana jon-net@usa.net Microsoft Sitebuilder Network Level 1 Member - HTML Writer's Guild Member