function DienstTrigger(divId) {

	var contentBox = document.getElementById(divId);
	var contentHide;

	// Alle knoppen initialiseren
	document.getElementById('btnLeidinggeven').className = 'button';
	document.getElementById('btnCoachen').className = 'button';
	document.getElementById('btnCommercieleVaardigheden').className = 'button';
	document.getElementById('btnRetraiteInspiratie').className = 'button';


	// Knop class active geven
	var currentBtn = 'btn' + divId.substr(6, 30);
	document.getElementById(currentBtn).className = 'active button';
	
	if(contentBox.style.display == 'block') {
		contentHide = true;
		document.getElementById(currentBtn).className = 'button';
	}

	// ALLE VELDEN VERBERGEN
	document.getElementById('dienstLeidinggeven').style.display = 'none';
	document.getElementById('dienstCoachen').style.display = 'none';
	document.getElementById('dienstCommercieleVaardigheden').style.display = 'none';
	document.getElementById('dienstRetraiteInspiratie').style.display = 'none';
		
	if(contentHide == true) {
		contentBox.style.display = 'none';
	} else {
		contentBox.style.display = 'block';
	}
	
}

function CheckContactForm(action) {
	var inputName = document.getElementById('name').value;
	var inputEmail = document.getElementById('emailaddress').value;
	var inputSubject = document.getElementById('subject').value;
	var inputMessage = document.getElementById('message').value;
	
	var labelName = document.getElementById('labelName');
	var labelEmail = document.getElementById('labelEmail');
	var labelSubject = document.getElementById('labelSubject');
	var labelMessage = document.getElementById('labelMessage');
	var errorBox = document.getElementById('errorBox');
	var errors;
	var emailRegExp = /^[^@]+@[^@]+.[a-z]{2,}$/i;
	
	if(errorBox.innerHTML.length > 7 || action == 'submit') {
		if(inputName == '') {
			labelName.style.color = '#F00';
			errors += '- Er is geen naam ingevoerd<br />';
		} else {
			labelName.style.color = '#000';
		}
	
		if(inputEmail.search(emailRegExp) == -1) {
			labelEmail.style.color = '#F00';
			errors += '- Er is geen geldig emailadres ingevoerd<br />';
		} else {
			labelEmail.style.color = '#000';
		}
		
		if(inputSubject == '') {
			labelSubject.style.color = '#F00';
			errors += '- Er is geen onderwerp ingevoerd<br />';
		} else {
			labelSubject.style.color = '#000';
		}
	
		if(inputMessage == '') {
			labelMessage.style.color = '#F00';
			errors += '- Er is geen bericht ingevoerd<br />';
		} else {
			labelMessage.style.color = '#000';
		}
	}

	if(errors) {
		if(errorBox.innerHTML.length > 7 || action == 'submit') {
			errorBox.style.display = 'block';
			errorBox.style.fontWeight = 'bold';
			errorBox.style.color = '#F00';
			errorBox.innerHTML = '<p>' + errors.substring(9, errors.length-6) + '<\/p>';
			if(action == 'submit') {
				alert('Het formulier is niet correct ingevuld');
			}
		}
			return false;
	} else {
		errorBox.innerHTML = '';
		return true;
	}

}