function categorie_changed() {
	document.getElementById('merk').value = ''; 
	document.getElementById('type').value = ''; 
	document.getElementById('f_submitted').value = 0; 
	document.getElementById('f_search').submit(); 
}

function merk_changed() {
	document.getElementById('type').value = ''; 
	document.getElementById('f_submitted').value = 0; 
	document.getElementById('f_search').submit(); 
}