form_verzonden = 0;
function test(velden,check_velden) {
  if (velden.email.value.indexOf("@")  == -1  ||
      velden.email.value.indexOf(".")  == -1  ||
      velden.email.value.length         <  6  ||
      velden.email.value.indexOf(" ")   >  0  ||
      velden.email.value.indexOf(",")   >  0  ||
      velden.email.value.indexOf("'")   >  0  ||
      velden.email.value.indexOf("/")   >  0  ||
      velden.email.value.indexOf("\\")  >  0  ||
      velden.email.value.indexOf("<") != -1 ||
      velden.email.value.indexOf(">") != -1 ||
      velden.email.value.indexOf("@") > velden.email.value.lastIndexOf(".")
     ) {
    e_mail_ok = 0;
  } else {
    e_mail_ok = 1;
  }
  base_check = 0;
  for(i=0;i<check_velden.length;i++) {
  	if (typeof(velden[check_velden[i]]) != 'undefined' && velden[check_velden[i]].value.length < 2 ) {
      alert("De/uw "+check_velden[i]+" ontbreekt.");
      base_check = 1;
  		velden[check_velden[i]].focus();
      i = check_velden.length;
  	}
  }
  if (base_check) { } else // als het hierboven al mis ging, niet nog meer fouten geven...

  if (e_mail_ok == 0 && velden.email.value.length > 0 )
  { alert("Uw e-mailadres is onjuist.");
    velden.email.focus();
  } else

  {
    if (form_verzonden == 0) {
      form_verzonden = 1;
      return (true);
    }
  }
  return (false);
}