function buttonHover(number) {
    
    document.getElementById('page-button-'+number+'').style.backgroundColor = '#151515'; 
    document.getElementById('menu').style.margin = '0';    
    document.getElementById('page-button-'+number+'').style.textDecoration = 'none'; 
    document.getElementById('page-a-button-'+number+'').style.color = '#6AD8FD';
    
    return;
}


function buttonDehover(number) {
    
    document.getElementById('page-button-'+number+'').style.backgroundColor = '#222222'; 
    document.getElementById('page-button-'+number+'').style.textDecoration = 'none'; 
    document.getElementById('page-a-button-'+number+'').style.color = '#FFFFFF'; 
    
    return;
}

function checkEmail(emailAddress) {
    var foundAtSymbol = 0;
    var foundDot = 0;
    var md;
    
    for (var x=0; x<emailAddress.length - 1; x++) {
        md = emailAddress.substr(x, 1);
    
        if (md == '@') {
            foundAtSymbol++;
        }
    
        if (md == '.' && foundAtSymbol == 1) {
            foundDot++;
        }
    }
    
    if (foundDot > 0 && foundAtSymbol == 1) {
        return true;
    } else{
        return false;
    }
}

function checkSendMail(){
    
    d = document.getElementById("sendMail");

    if(d.name.value==''){
        alert('U moet een naam invullen!');
        return false;
    }
    
    emailAddress = d.email.value;
    
    if(emailAddress==''){
        alert('U moet een emailadres invullen!');
        return false;
    }
    
    if(checkEmail(emailAddress)==false){
        alert('U moet een correct emailadres invullen! \n Gebruik een adres met @ en domeinnaam!');
        return false;
    }
    
    if(d.message.value==''){
        alert('U moet een bericht invullen!');
        return false;
    }
    
}