i cant seem to figure out how to use the master templates.

I add a master templatee , add some html (it only shows my stuff from inside body, the rest is gone? beginning html, body and eding tags)

Then i place this inside my html:

´

<placeholder name="content"/>

´

Then i ads this on the masters  child 'campaign letter'

'

<content phname="content">

put email content here

</content>

'

Add some dummy text inside the above content tag.

But when i send the newsletter nothing appears in the email?

What am i doing wrong?