function toggletopic() {
// showing category
document.getElementById('topicblock').style['display'] = 'block';
document.getElementById('topiclink').style['padding'] = '4px 12px 1px 12px';
document.getElementById('topiclink').style['border-width'] = '1px 1px 0px 1px';
document.getElementById('topiclink').style['border-style'] = 'solid';
document.getElementById('topiclink').style['border-color'] = '#999';
// hiding author
document.getElementById('authorblock').style['display'] = 'none';
document.getElementById('authorlink').style['padding'] = '4px 12px 0px 12px';
document.getElementById('authorlink').style['border-width'] = '1px 1px 1px 1px';
document.getElementById('authorlink').style['border-style'] = 'solid';
document.getElementById('authorlink').style['border-color'] = '#999';
}

function toggleauthor() {
// showing author
document.getElementById('authorblock').style['display'] = 'block';
document.getElementById('authorlink').style['padding'] = '4px 12px 1px 12px';
document.getElementById('authorlink').style['border-width'] = '1px 1px 0px 1px';
document.getElementById('authorlink').style['border-style'] = 'solid';
document.getElementById('authorlink').style['border-color'] = '#999';
// hiding category
document.getElementById('topicblock').style['display'] = 'none';
document.getElementById('topiclink').style['padding'] = '4px 12px 0px 12px';
document.getElementById('topiclink').style['border-width'] = '1px 1px 1px 1px';
document.getElementById('topiclink').style['border-style'] = 'solid';
document.getElementById('topiclink').style['border-color'] = '#999';
}