Hi,
In order for this to work properly, you need to a "default" banner that would show on the system pages (SiteMap, Register, Login, etc...).
I did this on the Norcross, GA High School website and the customer likes it quite a bit. Granted, their default banner is pretty basic but that's what they wanted and it does demonstrate how to do this.
The relevant markup for that site is (I included the logo in this markup because the design has the logo over the top of the banner, you don't have to do that):
<div id="wrapheader">
<portal:SiteLogo ID="SiteLogo" runat="server" />
<asp:Panel ID="divAlt1" runat="server" CssClass="altcontent1">
<asp:ContentPlaceHolder ID="altContent1" runat="server"></asp:ContentPlaceHolder>
</asp:Panel>
</div>
The CSS is (notice the background image in #wrapheader, that is the default image):
#wrapheader {
height: 318px;
color: #777;
float: left;
width: 1003px;
padding: 5px 0px 0px 0px;
background: #404040 url('head.jpg') top right no-repeat;
overflow: hidden;
position: relative;
}
#wrapheader > a, #wrapheader > a img.sitelogo {
position: absolute;
z-index: 101;
}
.altcontent1 {
z-index: 100;
position: absolute;
top: 0;
}
.altcontent1 .moduletitle {
visibility: hidden;
width: 990px;
position: absolute;
}
.altcontent1 .moduletitle a.ModuleEditLink {
visibility: visible;
background: #fff;
color: #000;
margin-right: 10px;
float: right;
}
.altcontent1 .moduletitle a.ModuleEditLink:hover {
text-decoration: none;
}
HTH,
Joe D.