var first_off = new Image();
first_off.src = "/images/structure/11_off.gif";
var first_on = new Image();
first_on.src = "/images/structure/11_on.gif";

var second_off = new Image();
second_off.src = "/images/structure/12_off.gif";
var second_on = new Image();
second_on.src = "/images/structure/12_on.gif";

var third_off = new Image();
third_off.src = "/images/structure/13_off.gif";
var third_on = new Image();
third_on.src = "/images/structure/13_on.gif";

var fourth_off = new Image();
fourth_off.src = "/images/structure/14_off.gif";
var fourth_on = new Image();
fourth_on.src = "/images/structure/14_on.gif";

var fifth_off = new Image();
fifth_off.src = "/images/structure/15_off.gif";
var fifth_on = new Image();
fifth_on.src = "/images/structure/15_on.gif";

var twofirst_off = new Image();
twofirst_off.src = "/images/structure/211_off.gif";
var twofirst_on = new Image();
twofirst_on.src = "/images/structure/211_on.gif";

var twosecond_off = new Image();
twosecond_off.src = "/images/structure/212_off.gif";
var twosecond_on = new Image();
twosecond_on.src = "/images/structure/212_on.gif";

var twothird_off = new Image();
twothird_off.src = "/images/structure/213_off.gif";
var twothird_on = new Image();
twothird_on.src = "/images/structure/213_on.gif";

var twofourth_off = new Image();
twofourth_off.src = "/images/structure/214_off.gif";
var twofourth_on = new Image();
twofourth_on.src = "/images/structure/214_on.gif";

var twofifth_off = new Image();
twofifth_off.src = "/images/structure/215_off.gif";
var twofifth_on = new Image();
twofifth_on.src = "/images/structure/215_on.gif";

function activate(imgName) {
  if ( eval(imgName + "_on.complete") ) {
    document.images[imgName].src = eval(imgName + "_on.src");
  }
}

function deactivate(imgName) {
  if ( eval(imgName + "_off.complete") ) {
    document.images[imgName].src = eval(imgName + "_off.src");
  }
}