function checkOfferForm() {
	var error = false;
	var aRequiredFields = new Array();
	aRequiredFields[0] = new Array(2);
	if (document.getElementById('bedrijfsnaam') == '[object HTMLInputElement]') {
		aRequiredFields[0]['name'] = 'bedrijfsnaam';
	} else {
		aRequiredFields[0]['name'] = 'naam';
	}
	aRequiredFields[0]['value'] = document.getElementById(aRequiredFields[0]['name']).value;
	aRequiredFields[1] = new Array(2);
	aRequiredFields[1]['name'] = 'adres';
	aRequiredFields[1]['value'] = document.getElementById(aRequiredFields[1]['name']).value;
	aRequiredFields[2] = new Array(2);
	aRequiredFields[2]['name'] = 'postcode';
	aRequiredFields[2]['value'] = document.getElementById(aRequiredFields[2]['name']).value;
	aRequiredFields[3] = new Array(2);
	aRequiredFields[3]['name'] = 'plaats';
	aRequiredFields[3]['value'] = document.getElementById(aRequiredFields[3]['name']).value;
	aRequiredFields[4] = new Array(2);
	aRequiredFields[4]['name'] = 'werkplaats';
	aRequiredFields[4]['value'] = document.getElementById(aRequiredFields[4]['name']).value;
	aRequiredFields[5] = new Array(2);
	aRequiredFields[5]['name'] = 'werkpostcode';
	aRequiredFields[5]['value'] = document.getElementById(aRequiredFields[5]['name']).value;
	aRequiredFields[6] = new Array(2);
	aRequiredFields[6]['name'] = 'werkplaats';
	aRequiredFields[6]['value'] = document.getElementById(aRequiredFields[6]['name']).value;
	
	for (i=0; i<7; i++) {
		if (aRequiredFields[i]['value'] == '') {
			error = true;
			document.getElementById(aRequiredFields[i]['name']+'_1').style.backgroundColor = 'red';
			document.getElementById(aRequiredFields[i]['name']+'_2').style.backgroundColor = 'red';
		}
	}
	if (!error) {
		document.forms['offerForm'].submit();
	} else {
		alert ('U dient alle velden in te vullen');
	}
}