UI Dialog - $.data is not a function

UI Dialog - $.data is not a function


I am getting the following message "$.data is not a function" and I
can't figure out the problem.
This is the js I include on the main file:
<script type="text/javascript" src="/js/jquery-pack.js"></script>
<script type="text/javascript" src="/js/jquery.ui/ui.dialog.js"></
script>
<script type="text/javascript" src="/js/jquery.dimensions.pack.js"></
script>
<script type="text/javascript" src="/js/jquery.ui/ui.mouse.js"></
script>
<script type="text/javascript" src="/js/jquery.ui/ui.draggable.js"></
script>
<script type="text/javascript" src="/js/jquery.ui/ui.resizable.js"></
script>
<script type="text/javascript" src="/js/heartbeat.js"></script>
<script type="text/javascript" src="/js/hot_lead_notify.js"></script>
This is my js file:
$(document).ready(function(){
    $.jheartbeat.set({
        url: "/hot_leads_notify.php",
        delay: 10000
    }, function () {
        $("#HeartBeatDIV").css("display", "block");
        $("#HeartBeatDIV").dialog({
            title: 'Are you sure?',
            buttons: {
                'Yes':
                    function() {
                        $(this).parents('.ui-dialog:first').dialogClose();
                        alert('You clicked \'Yes\'');
                    },
                'No': function() {
                    $(this).parents('.ui-dialog:first').dialogClose();
                    alert('You clicked \'No\'');
                }
            }
        });
        //$(this).hide().next().show();
    });
});