Showing a URL from a custom field

I’m trying to figure out how to show a link from a custom field.

What I need at the end of it, is a link at the end of each post which will be marked ‘Demo’ and clicking on it will take the user to the demo of whichever WordPress site I am discussing. This would be added in a custom field called ‘Demo’.

Looking around, I found various code for images, but could not find anything URL specific, and it just returns the URL of the page that the link will be on.

The code I’m using is:

ID, ‘Demo’, true ); ?>”>Demo

Is it something to do with the bit on $post or something? I don’t know, I’m coming at this is a complete newbie of custom fields.

I don’t want to show the full URL, just the word ‘Demo’.

Does anybody have a simple solution to this?

Thanks,

Joe