function submitGuestbookEntry(form) {
  if (form.naam.value == "") {
    alert("Vul je naam in!");
    return;
  }
  if (form.bericht.value == "") {
    alert("Vul een bericht in!");
    return;
  }
  if (form.codecheck.value == "") {
    alert("Vul een code in!");
    return;
  }  
  form.submit();
}

function submitContactForm(form) {
  if (form.emailadres.value == "") {
    alert("Vul email adres in!");
    return;
  }
  if (form.voornaam.value == "") {
    alert("Vul je voornaam in!");
    return;
  }
  if (form.achternaam.value == "") {
    alert("Vul achternaam in!");
    return;
  }
  if (form.bericht.value == "") {
    alert("Vul een bericht in!");
    return;
  }
  if (form.codecheck.value == "") {
    alert("Vul een code in!");
    return;
  }    
  form.submit();
}

function submitStembiljet() {
  var i;
  for (i = 1; i <= 5; i++) {
  	if (document.getElementById('artist_txt_' + i).value == "" && document.getElementById('artist_sel_' + i).value == 0 ) {
    		alert("Artiest " + i + " mist!");
    		return;
  	}
  	if (document.getElementById('song_txt_' + i).value == "" && document.getElementById('song_sel_' + i).value == 0) {
    		alert("Titel " + i + " mist!");
    		return;
  	}
		for (j=1; j<=5; j++) {    
			if (i!=j) { 
				if ( document.getElementById('song_sel_' + i).value > 0 && 
					 		document.getElementById('song_sel_' + j).value > 0 && 
					 		document.getElementById('song_sel_' + i).value == document.getElementById('song_sel_' + j).value ) {      
					alert("U mag niet 2x hetzelfde nummer stemmen! error 1");
					return;			
				}
				if ( document.getElementById('artist_sel_' + i).value == 0 && 
							document.getElementById('artist_sel_' + j).value == 0 &&
							document.getElementById('song_sel_' + i).value == 0 && 
							document.getElementById('song_sel_' + j).value == 0 &&
							document.getElementById('artist_txt_' + i).value == document.getElementById('artist_txt_' + j).value &&
							document.getElementById('song_txt_' + i).value == document.getElementById('song_txt_' + j).value ) {
					alert("U mag niet 2x hetzelfde nummer stemmen! error 2 - " + i + " - " + j);
					return;
				}
			}
		}
	}
  if (document.getElementById('name').value == "") {
    	alert("Vul je naam in!");
    	return;
  }
  if (document.getElementById('email').value == "") {
    	alert("Vul een werkend email adres in!");
    	return;
  }
  form.submit();
}

function handleEnter (field, event) { 
        var keyCode = event.keyCode ? event.keyCode : event.which ? event.which : event.charCode; 
        if (keyCode == 13) { 
            var i; 
            for (i = 0; i < field.form.elements.length; i++) 
                if (field == field.form.elements[i]) 
                    break; 
            i = (i + 1) % field.form.elements.length; 
            field.form.elements[i].focus(); 
            return false; 
        } 
        else 
        return true; 
}