vBulletin 4.2 spoiler code

gistfile1.html

<div style="margin:10px; margin-top:5px">
    <div style="margin-bottom:2px">
        <b>Spoiler</b>: <input class="button" type="button" value="Mutat" onclick="rejt(this)">
    </div>
    <div style="margin: 0px; padding: 6px; border: 1px inset;">
        <div class="spoiler" style="visibility: hidden;">
            {param}
        </div>
    </div>
</div>

<script>
function rejt(gomb){
    tag = gomb.parentNode.parentNode.getElementsByTagName('div')[1].getElementsByTagName('div')[0];
    if (tag.style.visibility != 'visible') {
        tag.style.visibility = 'visible';
        this.innerText = '';
        gomb.value = 'Rejt';
    }
    else {
        tag.style.visibility = 'hidden'; 
        this.innerText = '';
        gomb.value = 'Mutat';
    }
}
</script>