// VALIDATION ET ENVOI

  function validate_form()
    {
    validity = true; // assume valid

    if (!check_empty(document.form.QUESTION.value))
          { validity = false; alert('Ask your question, please.');
            document.form.QUESTION.focus();
            return validity ;
          }

    if (!check_empty(document.form.SOCIETE.value))
          { validity = false; alert('Enter your corporate name, please.');
            document.form.SOCIETE.focus();
            return validity ;
          }

     if (!check_empty(document.form.ADRESSE.value))
          { validity = false; alert('Enter your corporate address, please.');
            document.form.ADRESSE.focus();
            return validity;
          }

     if (!check_empty(document.form.ACTIVITE.value))
          { validity = false; alert('Enter your line of activity, please.');
            document.form.ACTIVITE.focus();
            return validity;
          }

    if (!check_empty(document.form.NOM.value))
          { validity = false; alert('Enter your name, please.');
            document.form.NOM.focus();
            return validity;
          }

    if (!check_empty(document.form.PRENOM.value))
          { validity = false; alert('Enter your first name, please.');
            document.form.PRENOM.focus();
            return validity;
          }
   

     if (!check_email(document.form.EMAIL.value))
          { validity = false; alert('Enter your e-mail address, please.');
            document.form.EMAIL.focus();
            return validity;
          }    
    }


  function check_empty(text) {
    return (text.length > 0); // returns false if empty
  }
  

  function check_email(adresse) {
    if ((adresse == "")
      || (adresse.indexOf ('@') == -1)
      || (adresse.indexOf ('.') == -1))
        return false;
    return true;
     }  

  // -->