customize GwtPollDialog to download excel

[xiaolinlee]

Hi，

i want to add a UI action to download data to excel by following code，

it works now, but how to capture if 'Cancel' button is clicked ?

function downloadExcel() {

    var checked = g_list.getChecked(); // get's the sys_id of the checked records

    var query = "sys_idIN" + checked.toString();

    var rows = checked.split(",").length;

    var view = g_list.getView();

    var dialog = new GwtPollDialog('x_presen_0_application_sum', query, rows, view, 'unload_excel_xlsx');

    dialog.execute();

}