Display alert message and redirect after click on accept

Question

Well, I have a page with links to reports. Whenever somebody clicks on one report, they can download the excel file. However, sometimes there are no fields to make a report;

Answer 1

This way it works`

   if ($result_array)
    to_excel($result_array->result_array(), $xls,$campos);
else {
    echo "";
    echo "";
}`