var current = 1;

function move(byWhat) {
    current += byWhat;
    if (current < 1) current = 5;
    if (current > 5) current = 1;
    show(current);
}

function show(nwhich) {
    current = nwhich;
    for (var dnum = 1; dnum <= 5; ++dnum) {
        var dv = document.getElementById("Div" + dnum);
        dv.style.display = (dnum == nwhich ? 'block' : 'none');
    }
    for (var dnum = 1; dnum <= 5; ++dnum) {
        var dv = document.getElementById("Tekst" + dnum);
        dv.style.display = (dnum == nwhich ? 'block' : 'none');
    }
    for (var dnum = 1; dnum <= 5; ++dnum) {
        var dv = document.getElementById("Klein" + dnum);
        dv.style.display = (dnum == nwhich ? 'none' : 'block');
    }
    for (var dnum = 1; dnum <= 5; ++dnum) {
        var dv = document.getElementById("KleinH" + dnum);
        dv.style.display = (dnum == nwhich ? 'block' : 'none');
    }
}