I'm a newbie at WordPress and php.
I want to remove the header from one or two pages only.
I saw this <http://wordpress.org/support/topic/how-to-remove-footer-from-individual-pages>

so I did this in my header.php file found under my theme folder

```
     <?php if( !is_page('18') ) :?> <!-- this is what I added -->
     <header class="banner">
     ...rest of html...
     </header>
     <?php endif;?>   <!-- this is what I added -->

```

Just for the sake of seeing if changes to this file were taking effect I also did `<?php if( false ) :?>` which was supposed to remove it from all pages but this didn't work either. 

Though I don't know the difference, I saw some different syntax and so also tried `<?php if(false) { ?>` and `<?php } ?>`

I am wondering if I have to do something else to have the changes take effect.

In case it matters, I am using the roots starter theme <http://roots.io/starter-theme/>
and WordPress 3.9.1