Create Custom Header for magento
<reference name="header"> <block type="page/header" name="header"> <action method="setTemplate"><template>cms/headers/about_us.phtml</template></action> </block> </reference> 
app/design/frontend/base/default/template/cms/headers/about_us.phtml and has the next contents:
4. Save all your changes and update the Shopping Cart page.
