Comment integrer du php dans une modal de bootstrap

             <?php
$duree= !empty($_POST['duree']) ? $_POST['duree'] : NULL;
                           //$duree = $_POST['duree'];

                           $ville=$duree;

                           ?> 

                        <form  method="post">

                           <label for="browser">choisi la ville de ton choix :</label>

                           <input list="browsers" name="duree" id="browser">

                           <datalist id="browsers">

                              <option value="Landelies, BE">

                              <option value="Gilly, BE">

                              <option value="Hourpes, BE">

                             

                              <option value="Hautbellain, LU">

                              <option value="Leithum, LU">

                              <option value="Huldange, LU">

                           </datalist>

                           <input type="submit" value="Valider" />

                        </form >

                        <script>
    $('form').on('submit', function(e) {
        if (validate()) { //your validation function here
            return true;
        }
        return false;
    });
    function validate(){
        if (!$('input[name=name]').val() || $('input[name=name]').val().length < 3) {
            return false;
        }
        return true;
    }
</script>

 $url = "https://api.openweathermap.org/data/2.5/weather?q=$ville&lang=fr&units=metric&appid=e30eac7b1e60d534d109bfad513a4d9a";

// Create an event listener to catch "when the form is submited"
$('.modal-body form').submit(function(event) {
    // to stop the form from submitting (and the page reloading, so the modal will not close)
    event.preventDefault(); 

    // Call server manually and send form data (see Mikey's comment)
    $.post('my.url.com/file.php', $(this).serialize(), function(err, result) {
      if (err) { 
        // Display error on form 
      } else {
        // Success... Redirect ?
        window.location = 'my.new.url/path.html'
      }
    })
});