Question: i see a lot of web site that.. remember when i return without using registration. 
I think they save cookies or something... 
So i'm asking you: in asp.net / vb.net how can i save the id of a user ? 
What are the command to do this ? 
Thanks in advance...

Answer: 
MSDN - <http://msdn.microsoft.com/en-us/library/ms178194.aspx>

Here is some VB.NET to read/write cookies. Pretty straight forward:

```
Sub SubmitBtnWrite_Click(Sender As Object, E As EventArgs)
    Response.Cookies("TestCookie1").Expires = "5/1/2010"
    Response.Cookies("TestCookie1").Value = _
        "The cookie stuff."
    Response.Cookies("TestCookie2").Expires = "5/1/2010"
    Response.Cookies("TestCookie2").Value = _
        "More cookie stuff." End Sub

Sub SubmitBtnRead_Click(Sender As Object, E As EventArgs)
Dim I as integer
For I = 0 to Request.Cookies.Count - 1
    lblMessage1.Text = lblMessage1.Text  _
        & Request.Cookies.Item(I).Name & ": " _
        & Request.Cookies.Item(I).Value & "<BR>"
Next End Sub

```
SLaks is correct - use cookies. The [Login](http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.login.aspx) control has this functionality built in.