for example (VB .Net):
Used to move coins from your MTGox account to your wallet
Dim postArray() As Byte
postString = "name=" & username & "&pass=" & password & "&group1=BTC" & "&btca= " & address & "&amount=" & amount
postArray = System.Text.Encoding.GetEncoding(1252).GetBytes(postString)
myURL = "https://mtgox.com/code/withdraw.php?"
winHttpReq = CreateObject("WinHttp.WinHttpRequest.5.1")
winHttpReq.settimeouts(60000, 60000, 60000, 60000)
winHttpReq.Open("POST", myURL, False)
winHttpReq.SetRequestHeader("Content-Type", "application/x-www-form-urlencoded")
winHttpReq.Send(postArray)
html = winHttpReq.responseText