Using SharpZipLib to extract Zip File

I'm trying to extract a zip file from within asp.net, after searching for a while using everyone fav search engine "the you know who" :) , i found this great library call sharpZipLib, and yes it's free
You can download it here :

http://www.icsharpcode.net/OpenSource/SharpZipLib/

to use it just add sharpZipLib.dll reference in your project, and then create a function to extract it.

Here are my function to extract the zip file :

        public ArrayList  ExtractZipFile(string zipFileName, string extractFolder)
       {
           FileStream inputZipStream = new FileStream(zipFileName,FileMode.Open);      
           ArrayList fileNameList = new ArrayList();
           try
           {
               ZipInputStream zipStream = new ZipInputStream(inputZipStream);
               ZipEntry entryFile = null;
               //loop for all the file in zip
               while((entryFile = zipStream.GetNextEntry()) != null)
               {
                   FileStream outPutStream = new FileStream(extractFolder + entryFile.Name  ,FileMode.Append);
                   int size = 2048;
                   byte[] data = new byte[2048];
                   while (true)
                   {
                       size = zipStream.Read(data, 0, data.Length);
                       if (size > 0)
                       {
                           outPutStream.Write(data, 0, size);
                       }
                       else
                       {
                           break;
                       }
                   }
                   outPutStream.Close();
                   fileNameList.Add(entryFile.Name);
               }
           }
           catch(Exception ex)
           {
               throw ex;
           }
           finally
           {
               inputZipStream.Close();
           }

           return fileNameList;
       }