Disabling Auto-Complete on ASP.NET Forms

To turn off auto-complete for your entire form, all you need to do is add an attribute to your form tag, like this:

<form id="Form1" method="post" runat="server" autocomplete="off">

The HTML INPUT tags also support the use of autocomplete=off and since the control renders as INPUT tags then you can use it to set it on a control by control basis. Just add it to the TextBox at design-time (but note that VS.NET will underline it with a squiggly saying that textbox does not have an attribute for autocomplete - but it will still work):

<asp:TextBox Runat="server" ID="Textbox1" autocomplete="off"></asp:TextBox>

or at runtime:

Textbox1.Attributes.Add("autocomplete", "off");