Option1: Using
Page.Master.FindControl()
Step1: Below code present in your mater page for menu only
<form id="form1" runat="server">
<div id="divTemp" runat="server">
Your menu here
</div>
</form>
Step2: Below need to present in your child/content page Page_Load()
protected void Page_Load(object sender, EventArgs e)
{
Control myControlMenu = Page.Master.FindControl("divTemp");
if(myControlMenu != null)
{
myControlMenu.Visible = false;
}
}
Option2: Create two master pages - one(master1.master) for login page and another one(master2.master) for other pages. You can use
master1
for pages like help page, contact us page because in those we don't need actual menus.
Choose one them which is feasible for you.