<script>
 
    // initialization of the layout
    var dhxLayout = new dhtmlXLayoutObject("parentId", "3L");
    ...
    // showing a header
    dhxLayout.cells("a").showHeader();
    // hiding a header
    dhxLayout.cells("a").hideHeader();
    // getting header's state
    var isVisible = dhxLayout.cells("a").isHeaderVisible();
    // setting text
    dhxLayout.cells("a").setText("New Text");</script>