/*-------------------------------*
 *                               *
 * for expand menu(side menu)    *
 *                               *
 *-------------------------------*/
function showHide(id) {

  var headerID = 'header' + id;
  var menuID   = 'menu' + id;

  if ( document.getElementById(menuID).style.display == "none" ) {
    document.getElementById(menuID).style.display              = "block";
    document.getElementById(headerID).style.backgroundPosition = "0px -30px";
  }
  else {
    document.getElementById(menuID).style.display              = "none";
    document.getElementById(headerID).style.backgroundPosition = "0px 0px";
  }
}