Problem with event firing

Problem with event firing

I'm in the process of migrating from Prototype to jQuery, and have run into a weird issue. The .on() event I'm trying to register only works if I use the older Prototype onLoad. If I switch to the jQuery .ready on page load the event doesn't register:

function HOAM_messageboardInit () {
    if ($j('#message_history').length) {
        $j('#message_history').parent().find('li').eq(2).on ('click', HOAM_messageHistory);
    }
}

function HOAM_messageHistory () {
    $j.ajax({
    type: "GET",
    url: '/hoam/scripts/messageboard/messageHistory.php',
    data: 'id=' + $j('#messageboard\\|id').val(),
    success: function (data) {
        $j('#message_history').html(data);
    }
    });
}

Event.observe (window, 'load', HOAM_messageboardInit, false);
//$j(document).ready (HOAM_messageboardInit, false);



Any ideas? As written above it works fine. Commenting out the Event.observe and using the jQuery .ready call instead doesn't. In both cases, the HOAM_messageboardInit function is called and runs (verified using a simple alert), but the $j('#message_history') .on() call doesn't register.