var menu = new Array("leistungsbild","unternehmen","tragwerksplanung","bautech"); 

  function disp(wert) 
    { 
    for (i=0;i < menu.length; i++) 
      { 
      if (menu[i] != wert) 
         { 
         document.getElementById(menu[i]).style.display = 'none'; 
         } 
      } 
    if (wert == 0) 
      { 
      return; 
      } 
    if (document.getElementById(wert).style.display == 'block') 
      { 
      document.getElementById(wert).style.display = 'none'; 
      } 
    else 
      { 
      document.getElementById(wert).style.display = 'block'; 
      } 
    } 
  var submenu = new Array("sub"); 


  function dispSub(wert) 
    { 
    for (i=0;i < submenu.length; i++) 
      { 
      if (submenu[i] != wert) 
         { 
         document.getElementById(submenu[i]).style.display = 'none'; 
         } 
      } 
    if (wert == 0) 
      { 
      return; 
      } 
    if (document.getElementById(wert).style.display == 'block') 
      { 
      document.getElementById(wert).style.display = 'none'; 
      } 
    else 
      { 
      document.getElementById(wert).style.display = 'block'; 
      } 
    }