function showdiv(node_id) {
   var ban = document.getElementById(node_id);
   ban.style.display="block";
   var ban2 = document.getElementById(node_id + "_minus");
   ban2.style.display="block";
   var ban3 = document.getElementById(node_id + "_plus");
   ban3.style.display="none";
}

function hidediv(node_id) {
   var ban = document.getElementById(node_id);
   ban.style.display="none";
   var ban2 = document.getElementById(node_id + "_minus");
   ban2.style.display="none";
   var ban3 = document.getElementById(node_id + "_plus");
   ban3.style.display="block";
}