// Only script specific to this form goes here.
// General-purpose routines are in a separate file.
  function validateOnSubmit() {
    var elem;
    var errs=0;
    // execute all element validations in reverse order, so focus gets
    // set to the first one in error.
    if (!validateTelnr  (document.forms.demo.telnr, 'inf_telnr', true)) errs += 1; 
 
    if (!validateEmail  (document.forms.demo.email, 'inf_email', true)) errs += 1; 
    if (!validatePresent(document.forms.demo.from,  'inf_from'))        errs += 1; 
    if (!validatePresent(document.forms.demo.surname,  'inf_surname'))        errs += 1;
    if (errs>1)  alert('There are fields which need correction before sending');
    if (errs==1) alert('There is a field which needs correction before sending');

    return (errs==0);
  };