[support] Nid in URL - How?

[John Thomas]

Executive Summary:  I need help constructing a url that includes the 
current nid.

Details:
I have a footer in a view as follows:

<a href="/node/add/task">Add task.</a>
<hr>
Input Format: Filtered HTML

I would like a footer which includes a variable (the current nid) as 
follows (but this does not work).

<a href="/node/add/task&proj_fill[]=$nid">Add related task.</a>
<hr>
Input Format: Filtered HTML

I have tried a variety of things, but cannot seem to get it to work. 
For example, this does not seem to work.

<a href="/node/add/task&proj_fill[]=$nid">Add related task.</a>
<hr>
Input Format: PHP code

Would you help me construct a url that includes the current nid?

-- 
Sincerely,
John Thomas