I think I got it with this: <?php if (arg(0) == 'node' && is_numeric(arg(1))) $nodeid = arg(1); echo '<a href="/node/add/task&proj_fill[]=', urlencode($nodeid), '">Add task.</a><hr>'; ?> Input Format: php
By the way, I had disabled the PHP input format, but the input format choice was still there. IMHO, the uninstall of PHP Input Filter should remove the input format it creates with its install.