function switchBoardsTab( onTabId, offTabId, params ){
    setCss( onTabId, onTabId + "_dialogTabOn" );
    if( offTabId != null ){
        setCss( offTabId, offTabId + "_dialogTabOff" );
    }
    /* dependent upon prototype.js */
    loadHtml( 'divBoards', 'Boards_' + onTabId + '.aspx', params );
}
/* set css class */
function setCss( elementId, cssClassName ){
    var el = document.getElementById( elementId );
    el.setAttribute( "class", cssClassName );
    /* IE does not recognize class, rather className */
    el.setAttribute( "className", cssClassName );
}