function displayContent(id) 
{
	document.getElementById(id).style.display= 'block';
}
function noDisplayContent(id) 
{
	document.getElementById(id).style.display = 'none';
}

	function echeck(str) {

		var at="@"
		var dot="."
		var lat=str.indexOf(at)
		var lstr=str.length
		var ldot=str.indexOf(dot)
		
		if (str.indexOf(at)==-1){
		    return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		    return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    return false
		 }

 		 return true					
	}

	function checkForm() {
		var emailID=document.ContactForm.email
		var result = true;

		errorMessage = "Voer alstublieft de volgende velden in: \n";

		if ((document.ContactForm.name.value.length==0) || (document.ContactForm.name.value==null)) {
			result=false;
			errorMessage += "- Naam \n";
		}
		


		if (echeck(emailID.value)==false){
		result=false;
		errorMessage += "- Een geldige E-mail Adres \n";
		}
		
		if ((document.ContactForm.company.value.length==0) || (document.ContactForm.company.value==null)) {
			result=false;
			errorMessage += "- Bedrijfsnaam \n";
		}


		if ((document.ContactForm.question.value.length==0) || (document.ContactForm.question.value==null)) {
			result=false;
			errorMessage += "- Opmerking/Vraag\n";
		}


		if (!(result == true)) {
			alert(errorMessage);
		}
		return result;
	}

	function checkForm2() {
		var emailID=document.ContactForm.email
		var result = true;

		errorMessage = "Voer alstublieft de volgende velden in: \n";




		if (echeck(emailID.value)==false){
		result=false;
		errorMessage += "- Een geldige E-mail Adres \n";
		}

		if (!(result == true)) {
			alert(errorMessage);
		}
		return result;
	}

	function checkForm3() {
		var emailID=document.ContactForm.email
		var result = true;

		errorMessage = "Voer alstublieft de volgende velden in: \n";

		if ((document.ContactForm.surname.value.length==0) || (document.ContactForm.surname.value==null)) {
			result=false;
			errorMessage += "- Achternaam \n";
		}

		if ((document.ContactForm.between.value.length==0) || (document.ContactForm.between.value==null)) {
			result=false;
			errorMessage += "- Tussenvoegsel \n";
		}

		if ((document.ContactForm.initials.value.length==0) || (document.ContactForm.initials.value==null)) {
			result=false;
			errorMessage += "- Voorletters \n";
		}

		if ((document.ContactForm.name.value.length==0) || (document.ContactForm.name.value==null)) {
			result=false;
			errorMessage += "- Roepnaam \n";
		}

		if ((document.ContactForm.address.value.length==0) || (document.ContactForm.address.value==null)) {
			result=false;
			errorMessage += "- Adres \n";
		}

		if ((document.ContactForm.zipcode.value.length==0) || (document.ContactForm.zipcode.value==null)) {
			result=false;
			errorMessage += "- Postcode \n";
		}

		if ((document.ContactForm.city.value.length==0) || (document.ContactForm.city.value==null)) {
			result=false;
			errorMessage += "- Woonplaats \n";
		}

		if ((document.ContactForm.birthdate.value.length==0) || (document.ContactForm.birthdate.value==null)) {
			result=false;
			errorMessage += "- Geboortedatum \n";
		}

		if ((document.ContactForm.phone.value.length==0) || (document.ContactForm.phone.value==null)) {
			result=false;
			errorMessage += "- Telefoonnummer \n";
		}

		if ((document.ContactForm.address.value.length==0) || (document.ContactForm.address.value==null)) {
			result=false;
			errorMessage += "- Adres \n";
		}

		if (echeck(emailID.value)==false){
		result=false;
		errorMessage += "- Een geldige E-mail Adres \n";
		}

		if ((document.ContactForm.startdate.value.length==0) || (document.ContactForm.startdate.value==null)) {
			result=false;
			errorMessage += "- Beschikbaar vanaf \n";
		}

		if ((document.ContactForm.hours.value.length==0) || (document.ContactForm.hours.value==null)) {
			result=false;
			errorMessage += "- Aantal uur per week \n";
		}

		if ((document.ContactForm.motivation.value.length==0) || (document.ContactForm.motivation.value==null)) {
			result=false;
			errorMessage += "- Motivatie \n";
		}

		if (!(result == true)) {
			alert(errorMessage);
		}
		return result;
	}