how to display none through code behind

Question

I have tried this

login_div.Style("display") = "none";

But it's not working.how can I set the display of the div to none through code behind, in aspx I have a div:

<div id="login_div" runat="server">

Answer 1

I believe this should work:

login_div.Attributes.Add("style","display:none");

Answer 2

Try if this works:

Panel2.Style.Add("display", "none");