function show(foo) {
      if (document.getElementById(foo)) {
        document.getElementById(foo).style.display = "block";
      }
    }
    
    function hide(foo) {
      if (document.getElementById(foo)) {
        document.getElementById(foo).style.display = "none";
      }
    }

    function toggle(foo) {
      if (document.getElementById(foo)) {
        if (document.getElementById(foo).style.display == "block") {      
          hide(foo);
        } else {
          show(foo);
        }
      }
    }
    
    function hideslides(max) {
      for (var i = 1; i <= max; i++) {
        var slide = 'slide' + i;
        hide(slide);
      }
    }
    
    function showslide(focus, maxb) {
      for (var i = 1; i <= maxb; i++) {
        var slidename = 'slide' + i;
        var slide = 'slide' + i;
          if (i == focus) {
            show(slide);
          } else {
            hide(slide);
          }
      }
      return false;
    }