Custom Fields Adding an ID

Hello, I hope someone can help.

I want to put in a custom field, but I want it to relate to an id.
Do for example:

<div id="box"><p id="WANTTOGENERATEIDHERE">some text</p></div>

So in the PHP I have the above, but in ‘WANTTOGENERATEIDHERE’ I want to use custom fields to change that id.

Can this be done?
So far I am here: id="<?php $custom_values = get_post_custom(date); ?>"

Please help, I have a deadline tomorrow… ??

Thank you