Add javascript function to page

hello

One of my pages has a link that when it is pressed it should communicate with the DB. I have 2 files added to the root of my domain address – add.php, jquery.js.
in the wordpress page I have added below code:

<script src="jquery.js"></script>
<a href="add(true);">Click Me</a>
<script type="text/javascript">
function add(b){
   function operation;
}
</script>

But, in the page when I click on the link-Click Me- nothing happens.
please tell me what should I do ?