wordpress-Ajax通讯

This is the first time I do the ajax and I must confess that I am confused. What I want to do is to take the value of 3 Select html to make a request to my database that'll get me a score according to the desired choice. The purpose of using ajax is that I do not want the submit button and I want that when the value of one of my select changes only choose my result in my database changes according to the new value. So the hen I change a value in my select I call a javascript that takes values ​​from my select and pass ajax to my function.php which then makes a request with the values ​​of my Selects function and then returns the result of my request.

I have my html in archive page, my .js in external file and my php function is in function.php.

My problem is that dont working and i dont know why, i follow 5 tuto and all are different and confuse me.

Sorry for my English, this language is not my first language.

Now my code look like that:

javascript:

function showWidth($) {
  // get the value of my 3 html select
  var width1 = document.getElementById('width1').value;
  var width2 = document.getElementById('width2').value;
  var width3 = document.getElementById('width3').value;

  if (width1!="aucun" && width2!="aucun" && width3!="aucun") {
    $.ajax({
      ObjectName.ajaxurl,
      data: {
        action:'script_handle',
        width01 : width1,
        width02 : width2,
        width03 : width3
      },
      success:function(data) {
        // This outputs the result of the ajax request
        document.getElementById("result").innerHTML=console.log(data);
      },
      error: function(errorThrown){
        console.log(errorThrown);
      }
    });
  }
}

PHP (in function.php):

function widthcalculate(){
    if( isset($_REQUEST) ) {
      $width1 = $_REQUEST['width01'];
      $width2 = $_REQUEST['width02'];
      $width3 = $_REQUEST['width03'];
      // Let's take the data that was sent and do something with it
      global $wpdb;
      $where = "'".$width1."' AND camber = '".$width2."' AND handrim = '".$width3."'";
      $sql = $wpdb->get_results(
       "SELECT result FROM mc_widthCalculatorResult WHERE wheel = ".$where.""
      );
      foreach ($sql as $element) {
        echo $element->result;
      }
      echo $result;
      //print_r($_REQUEST);
    }
    die();
  }
  add_action( 'wp_ajax_script_handle', 'widthcalculate' ); // Hook for the WordPress Dashboard.
  add_action( 'wp_ajax_script_handle_nopriv', 'widthcalculate' ); // Hook for the user facing side of the site.

  function register_scripts() {
    wp_register_script( 'script-handle', $path_to_javascript_file, $dependencies, 'version', $in_footer = true );
    wp_enqueue_script( 'script-handle' );

    wp_localize_script( 'script-handle', 'ObjectName', array( 'ajaxurl' => admin_url( '/wp-admin/admin-ajax.php' ), 'parameter' => $whatever_you_want_to_pass ) );
  }

  add_action( 'enqueue_scripts', 'register_scripts' );