SELECT `dept_no`, sum(`salary`) AS `sum`
FROM `salaries` AS `s`
JOIN `dept_emp` AS `d`
ON `s`.`emp_no` = `d`.`emp_no`
WHERE `s`.`to_date` = '9999-01-01'
GROUP BY `d`.`dept_no`
ORDER BY `sum` DESC
LIMIT 1
$('#button').submit(function(event){
event.preventDefault();
$.ajax({
type: "POST",
url: "./index.php",
data: "action=addProject",
});
});