var table = document.getElementById('idList');
var selected = table.getElementsByClassName('selected');
var selectedId = 'None';
table.onclick = highlight;

function select(category) {
    var id = selectedId;
    if (id == 'None')
    {
        alert("Kein Eintrag ausgewaehlt!");
    }
    else
    {
        window.location.href = '/detail/?cat=' + category + '&id=' + id;
    }
}

function highlight(e) {
   if (selected[0]) selected[0].className = '';
   e.target.parentNode.className = 'selected';
   var tr = e.target.parentNode;
   selectedId = tr.getAttribute('id');
}