Link not asking user to confirm

Link not asking user to confirm

I have this code
echo '<div class="bottomright"><a href="?id='
. $topic_id
. '&part=5"><img src="../assets/icons/Comments-
edit.png" /></a><a href="?id='
. $topic_id
. '&part=6"><img src="../assets/icons/Lock.png" /></a><a
href="#" onclick="return confirm("Are you sure?")"><img
src="../assets/icons/Trash.png" /></a></div>';
When I click Trash.png it is supposed to ask "Are you sure"? But it
doesn't...
Am I missing something here?