var flag = new Array();

function treeMenu(id){
  var h = document.getElementById('subcat-' + id);
  if(flag[id] == 0 || !flag[id]) {
    h.style.display = 'block';
    flag[id] = 1;
  }else if(flag[id] == 1) {
    h.style.display = 'none';
    flag[id] = 0;
  }
}