function showscroll()
{
document.getElementById('scrolleft').style.visibility= 'visible';
}

function hidescroll()
{
document.getElementById('scrolleft').style.visibility= 'hidden';
}

function showwillem()
{
document.getElementById('naam').style.visibility= 'visible';
}

function hidewillem()
{
document.getElementById('naam').style.visibility= 'hidden';
}