HTML

onclick a tag

<a href='http://www.google.com' onclick='return check()'>check</a>

<script type='text/javascript'>
function check() {
    return false;
}
</script>

onclick on anchor tag

<a href='more.php' onclick='show_more_menu()'>More >>></a>

on click in a tag

<a onclick='newwin()'>Anchor</a>

a tag onclick

<a href="javascript:show_more_menu();">More >>></a>