Yes, it works for me. I’m using it on http://www.limhamnsff.se if you want to check out the source.
I made my own little fix and changed
Leaguemanager.setMatchBox = function( curr_index, operation, element, league_id, match_limit, widget_number, season, home_only, date_format ) {
to
function setMatchBox( curr_index, operation, element, league_id, match_limit, widget_number, season, home_only, date_format ) {
in leaguemanager.js
and
onclick='Leaguemanager.setMatchBox(
to
onclick='setMatchBox(
in widget.php
But I have no advanced Javascript skills and don’t know why you have used an Leaguemanager Object, but it might help you find the error.