add html to all pages

Question

I am creating a module and I want it should add a .phtml files contents to all pages what do I need to write in my layout.xml file to do this? I am unsuccessfully trying,

<?xml version="1.0"?>
<layout version="1.0.0">
    <default>
        <reference name="before_body_end">
            <block type="core/template" name="mypopup_block"  template="[namespace]/[module]/htmltoadd.phtml"></block>
        </reference>
    </default>
</layout>

here is the config.xml calling the layout file

<config>
...
<global>
<frontend>
    <layout>
        <updates>
            <[namespace]_[module module="[namespace]_[module">
                <file>[namespace]_[module].xml</file>
            </[namespace]_[module>
        </updates>
    </layout>
</frontend>
</global>