Question : HttpRequest does not send non visible fields...

I am sending an HTTPREQUEST object to c# code.  

I am saving some of the values to the database.  I have a text box called txtPono.  Everything has been working fine until I made that field visible = false.  This text box has a value, I just dont want the user to be able to see the data.  When I get to the insert statement in the database I get the following error:
            reqst["TxtPono"].ToString()      'reqst["TxtPono"]' is null      string

note, the text box is set to enabled.

Answer : HttpRequest does not send non visible fields...

its a property instead of Txtpono.Visible=false;
use Txtpono.Style.Add(HtmlTextWriterStyle.Display,"none");