I'm have a HTML page that loading a table and a dhtmlxgantt chart. The javascript function below works but now i want to load the gantt chart from a different html and display it through iframe.
How can I get the content_id from the main_page.html table and populate it on scheduler.html gantt chart 
Everyone helps is much appreciated
main_page.html
<table id="project-content-datatable">
    <tbody>
        <tr>
            <td class="project_content_id">1</td>
            <td class="project_content_id">2</td>
            <td class="project_content_id">3</td>      
        </tr>
    </tbody>
</table>
<div class="col-md-12" style="padding: 3px; margin: 0px;">
     <iframe src="/dashboard/projects/scheduler.html" height="330"; width="99%" style="border:2px  solid blue; border-radius: 5px;"></iframe>
</div>
scheduler.html
<div id="my_scheduler" style='width:1567px; height:325px;'></div>
javascript
$('#project-content-datatable').on('click', 'tr', function () {
    var content_id =$(this).closest('tr').children('td.project_content_id').text();
    initializeGantt(content_id)
    });
    gantt.config.xml_date = "%Y-%m-%d";
    function initializeGantt(content_id) {
        scheduler = gantt.init("my_scheduler", new Date('2017, 01, 01'), new Date('2017, 12, 31'));
        $.get("/dashboard/ganttchart_list/"+content_id+"/?format=json", function(result) { gantt.parse(prepareData(result)); });
    }
    initializeGantt();
 
    