function checkOwnerForm(form) {

	// regular expression to match alphanumeric characters and spaces 
	//var re	= /^[\w.a-zA-Z0-9 _\. \/-\']+$/; 
	var tel		= /^[0-9. -()+]{10,15}$/;
	var ere		= /^[_\.0-9a-z-]+@([0-9a-z][0-9a-z-]+\.)+[a-z]{2,6}$/;
	var pc		= /^[0-9]{4}[a-zA-Z]{2}$/;
	var pb		= /^[0-9]{1,6}$/;
	var amount	= /^[0-3]{1}$/;
	// validation fails if the input is blank
	/*
	  var cnt = -1;
    for (var i=form.coming.length-1; i > -1; i--) {
        if (form.coming[i].checked) {cnt = i; i = -1;}
    }
    if (cnt > -1) return form.coming[cnt].value;
    else return null;
	*/
	if(form.coming) {
	
		if(form.coming[0].checked) {
		
			if(form.aantal_gasten.value.substr(0,1) == "0") {
			
				alert("Er zijn nog geen gasten ingevuld!\n\nPlease fill in your guests!");
				return false;
			
			}
		
		}
	
		if(form.coming[1].checked) {
		
			if(form.aantal_gasten.value.substr(0,1) != "0") {
			
				alert("Als er geen gebruik word gemaakt van de uitnodiging, wilt u dan eerst alle gasten verwijderen!\n\nIf you wish to not use your invitation than please remove all the guests first!");
				return false;
			
			}
		
		}
	
	}
	
	if(form.telefoon) {
	
		if(form.telefoon.value.length > 0) {
	
			if(form.telefoon.value.length < 1) {	
		
				alert("Telefoon is niet ingevuld!\n\n");
				form.telefoon.focus();
				return false;	
			
			} 
		
			if(form.telefoon.value.substr(0,1)!="0") {	
		
				alert("Telefoonnummer moet met een nul beginnen!\n\nPhone number starts with a zero!");
				form.telefoon.focus();
				return false;	
			
			} 
		
			if(form.telefoon.value.length < 10) {	
		
				alert("Ongeldig telefoonnummer. min. 10 cijfers\n\nInvalid phone number. min. 10 digits.");
				form.telefoon.focus();
				return false;	
			
			} 
		
		}
	
	}
	
	if(form.mobiel) {
	
		if(form.mobiel.value.length > 2) {
	
			if(form.mobiel.value.length < 1) {	
		
				alert("Telefoon is niet ingevuld!\n\n");
				form.mobiel.focus();
				return false;	
			
			} 
		
			if(form.mobiel.value.substr(0,1)!="0") {	
		
				alert("Mobiele telefoonnummer moet met een nul beginnen!\n\nMobile phone number starts with a zero!");
				form.mobiel.focus();
				return false;	
			
			} 
		
			if(form.mobiel.value.length < 10 && form.mobiel.value.length > 2) {	
		
				alert("Ongeldig mobiele telefoonnummer. min. 10 cijfers\n\nInvalid mobile phone number. min. 10 digits.");
				form.mobiel.focus();
				return false;	
			
			} 
		
		}
	
	}
	
	if(form.email) {
	
		if(form.email.value.length < 1) {	
		
			alert("E-mail is niet ingevuld!\n\nPlease fill in your email address");
			form.email.focus();
			return false;	
			
		} 
		
		if(form.email.value.length > 1) {	
		
			emailOk = isEmail(form.email.value);
				
		} 
		
		
		if(!emailOk) { alert("Ongeldig e-mailadres!\n\nInvalid email address!");
		
			form.email.focus();
			return false;	
			
		} 
		
	}
	
	return true; 
	 
} 

function checkLoginValue(form) {	
	
	if(form.email) {
	
		if(form.email.value.length < 1) {	
		
			alert("e-mail is verplicht!");
			form.email.focus();
			return false;	
			
		} 
		
		if(form.email.value.length > 1) {	
		
			emailOk = isEmail(form.email.value);
				
		} 
		
		
		if(!emailOk) { 
			
			alert("ongeldig e-mailadres");
			
			form.email.focus();
			return false;	
			
		} 
		
	}
	
	if(form.pw) {
	
		if(form.pw.value.length < 1)	{	
		
			alert("zonder password kunt u niet inloggen!");		
			form.pw.focus();			
			return false;	
			
		} 
		
	}
	
	return true; 
	 
} 

function checkContactValue(form) {	

	// regular expression to match alphanumeric characters and spaces 
	//var re	= /^[\w.a-zA-Z0-9 _\. \/-\']+$/; 
	var tel		= /^[0-9. -()+]{10,15}$/;
	var ere		= /^[_\.0-9a-z-]+@([0-9a-z][0-9a-z-]+\.)+[a-z]{2,6}$/;
	var pc		= /^[0-9]{4}[a-zA-Z]{2}$/;
	var pb		= /^[0-9]{1,6}$/;
	var amount	= /^[0-3]{1}$/;
	// validation fails if the input is blank
	
	if(form.voornaam) {
	
		if(form.voornaam.value.length < 1)	{	
		
			alert("voornaam is verplicht!");		
			form.voornaam.focus();			
			return false;	
			
		} 
		
	}
	
	if(form.achternaam) {
	
		if(form.achternaam.value.length < 1)	{	
		
			alert("achternaam is verplicht!");		
			form.achternaam.focus();			
			return false;	
			
		} 
		
	}
	
	if(form.telefoon) {
		
		if(form.telefoon.value.length < 10) {	
		
			alert("ongeldig telefoonnummer. min. 10 cijfers");
			form.telefoon.focus();
			return false;	
			
		} 
	
		if(form.telefoon.value.length > 0) {	
		
			if(form.telefoon.value.substr(0,1)!="0") {	
		
				alert("telefoonnummer begint met een nul");
				form.telefoon.focus();
				return false;	
			
			} 
		
		}
	
	}
	
	if(form.email) {
	
		if(form.email.value.length < 1) {	
		
			alert("e-mail is verplicht!");
			form.email.focus();
			return false;	
			
		} 
		
		if(form.email.value.length > 1) {	
		
			emailOk = isEmail(form.email.value);
				
		} 
		
		
		if(!emailOk) { 
			
			alert("ongeldig e-mailadres");
			
			form.email.focus();
			return false;	
			
		} 
		
	}
	
	if(form.vraag) {
	
		if(form.vraag.value.length < 1)	{	
		
			alert("vraag is verplicht!");		
			form.vraag.focus();			
			return false;	
			
		} 
		
	}
	
	if(form.vercode) {
	
		if(form.vercode.value.length < 1)	{	
		
			alert("verificatie is verplicht!");		
			form.vercode.focus();			
			return false;	
			
		}
		
	}
	
	return true; 
	 
} 

function checkEzineValue(form) {	

	// regular expression to match alphanumeric characters and spaces 
	//var re	= /^[\w.a-zA-Z0-9 _\. \/-\']+$/; 
	var tel		= /^[0-9. -()+]{10,15}$/;
	var ere		= /^[_\.0-9a-z-]+@([0-9a-z][0-9a-z-]+\.)+[a-z]{2,6}$/;
	var pc		= /^[0-9]{4}[a-zA-Z]{2}$/;
	var pb		= /^[0-9]{1,6}$/;
	var amount	= /^[0-3]{1}$/;
	// validation fails if the input is blank
	
	if(form.telefoon) {
	
		if(form.telefoon.value.length > 0) {	
		
			if(form.telefoon.value.length < 10) {	
		
				alert("ongeldig telefoonnummer. min. 10 cijfers");
				form.telefoon.focus();
				return false;	
			
			} 
		
			if(form.telefoon.value.substr(0,1)!="0") {	
		
				alert("telefoonnummer begint met een nul");
				form.telefoon.focus();
				return false;	
			
			} 
		
		}
	
	}
	
	if(form.email) {
	
		if(form.email.value.length < 1) {	
		
			alert("e-mail is verplicht!");
			form.email.focus();
			return false;	
			
		} 
		
		if(form.email.value.length > 1) {	
		
			emailOk = isEmail(form.email.value);
				
		} 
		
		
		if(!emailOk) { 
			
			alert("ongeldig e-mailadres");
			
			form.email.focus();
			return false;	
			
		} 
		
	}
	
	return true; 
	 
} 

function checkAddValue(form) {	
	// place any other field validations that you require here
	// validate myradiobuttons
	myOption = -1;
	for (i=form.formaat.length-1; i > -1; i--) {
		if (form.formaat[i].checked) {
			myOption = i; i = -1;
		}
	}
	if (myOption == -1) {
		alert("Je moet een formaat selecteren");
		return false;
	}
	
	return true; 
 
} 
	
function isEmail( url ) {
	var a,b,c,d,e,f,g,h,i,j,k,l,m,n,o
	if (url != null && url != "") {
		a = url.lastIndexOf("@");
		b = url.lastIndexOf(".");
		c = url.indexOf(":");
		d = url.indexOf("/");
		e = url.substring(0,a);
		f = e.indexOf("@");
		g = url.substring(a+1,url.length);
		h = g.indexOf("[");
		i = g.indexOf("]");
		j = g.indexOf("<");
		k = g.indexOf(">");
		l = url.substring(a+1,b);
		m = url.substring(b+1,url.length);
		n = url.substring(0,a);
		p = url.indexOf(",");
		q = url.indexOf(" ");		
		r = url.indexOf("@.");		
		o = 0;
		if (a > b) {o++};
		if (c != -1) {o++};
		if (d != -1) {o++};		
		if (f != -1) {o++};
		if (h != -1) {o++};
		if (i != -1) {o++};
		if (j != -1) {o++};
		if (k != -1) {o++};
		if (m.length < 2) {o++};
		if (n.length < 1) {o++};
		if (p != -1) {o++};
		if (q != -1) {o++};		
		if (r != -1) {o++};		
		if (o == 0) {
			return true; }
		else {
			return false; }
		}
	else {
	 	return false; }
}