function checkinput() {
	if(!checkMailAddress(document.getElementById("emailveld").value)) {
		alert("Uw E-mail adres klopt niet");
		return false;
	}
	
	return true;
}

function checkMailAddress(email) {
    if (email == "" || email == " ") {
        return false;
    } else {
        if (email.indexOf("@") > 0 && email.indexOf(".") > 0) {
            return true;
        } else {
            return false;
        }
    }
}