i have my code like this :

<?php
include 'fonctions.php';

?>
<input type="button" onClick="chauffeur_info(330);" />
  <h1 id="header"></h1>
  <script>
    function chauffeur_info(matricule){
    console.log(matricule);
    var result = "<?php echo get_nom_prenom_chauffeur(matricule); ?>";
    document.getElementById("header").innerHTML = result;

    }
  </script>

when i call it like that it gives me an error, but when i do :

var result = "<?php echo get_nom_prenom_chauffeur(330); ?>";
document.getElementById("header").innerHTML = result;

it's working perfectly, any idea why it's not working.

PS: console.log is giving me the right value

Thanks in advance