Thank you Bruce,
After reading your post and playing with the example app, I was able to post a file to my web server very easily.
ThisWebClient.SetAllHeadersDefault()
ThisWebClient.CanUseProxy = TRUE
ThisWebClient.HeaderOnly = FALSE
ThisWebClient.AsyncOpenUse = TRUE ! Use AsyncOpen 12 seconds (recommended)
ThisWebClient.AsyncOpenTimeOut = 1200 ! Up to 12 seconds to connect
ThisWebClient.InActiveTimeout = 9000 ! Set IdleTimeout 90 seconds
ThisWebClient.SSLCertificateOptions.CertificateFile = ''
ThisWebClient.SSLCertificateOptions.PrivateKeyFile = ''
ThisWebClient.SSLCertificateOptions.DontVerifyRemoteCertificateCommonName = TRUE
ThisWebClient.SSLCertificateOptions.DontVerifyRemoteCertificateWithCARoot = TRUE
ThisWebClient.OptionAutoCookie = 1
ThisWebClient.SetValue('UploadFile','c:\temp\mytestfile.txt',Net:IsFile)
ThisWebClient.SetValue('pressedButton','save_btn')
ThisWebClient.Post('
https://localhost', '')