function checkForm(form){
	var msg = "";
	var pattern_postcode=/^[a-zA-Z ]{1,2}[0-9]{1,2} [0-9][a-zA-Z ]{2}$/;
	var pattern_email=/^([a-zA-Z0-9_.-])+@([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+/;
	var pattern_mobile=/^\+?[0-9]{11,13}$/;

	if(!pattern_postcode.test(form.postcode.value)) msg+="Postcode (like: AB1 2CD, A1 2BC or AB12 3CD)\n";
	if(!pattern_email.test(form.email.value)) msg+="Email address\n";

    // if number is 07* -> +447*..
    if(form.mobile.value.substring(0,2) == "07") form.mobile.value = "+447" + form.mobile.value.substring(2);
    else if(form.mobile.value.substring(0,2) == "31") form.mobile.value = "+31" + form.mobile.value.substring(2);
    else if(form.mobile.value.substring(0,2) == "44") form.mobile.value = "+44" + form.mobile.value.substring(2);

    if (form.mobile.value.substring(0,3) != "+31" && form.mobile.value.substring(0,3) != "+44") msg+="Invalid mobile number (e.g. +447123456789)\n";
	else if((!pattern_mobile.test(form.mobile.value) && form.mobile.value!="")) msg+="Mobile number (e.g. +447123456789)";

	if(msg!=""){
		msg = "Please check the following form fields:\n\n" + msg;
		alert(msg);
		return false;
	}
	return true;
}

function checkTaf(form){
	var msg = "";
	var pattern_email=/^([a-zA-Z0-9_.-])+@([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+/;

	if(!pattern_email.test(form.myemail.value)) msg+="Your email address\n";
	if(form.myname.value=="") msg+="Your name\n";

	if(!pattern_email.test(form.friendemail_1.value)||form.friendname_1.value==""){
		msg+="A complete profile for your friend.\n";
	}

	if(form.friendname_2.value!=""||form.friendemail_2.value!=""){
		if(!pattern_email.test(form.friendemail_2.value)||form.friendname_2.value==""){
			msg+="A complete profile for your second friend or leave empty.\n";
		}
	}

	if(form.friendname_3.value!=""||form.friendemail_3.value!=""){
		if(!pattern_email.test(form.friendemail_3.value)||form.friendname_3.value==""){
			msg+="A complete profile for your third friend or leave empty.\n";
		}
	}

	if(msg!=""){
		msg = "Please fillout the following form fields:\n\n" + msg;
		alert(msg);
		return false;
	}
	return true;
}

function checkChange(form){
	var msg = "";
	var pattern_email=/^([a-zA-Z0-9_.-])+@([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+/;

	if(!pattern_email.test(form.email.value)) msg+="Email address\n";

	if(msg!=""){
		msg = "Please fillout the following form fields:\n\n" + msg;
		alert(msg);
		return false;
	}
	return true;
}