// pre-load main navigation rollover images

if (document.images) {

  buttonA_on = new Image(); buttonA_off = new Image(); 
  buttonB_on = new Image(); buttonB_off = new Image(); 
  buttonC_on = new Image(); buttonC_off = new Image();
  buttonD_on = new Image(); buttonD_off = new Image();
  buttonE_on = new Image(); buttonE_off = new Image();
  buttonF_on = new Image(); buttonF_off = new Image();

  buttonA_on.src = "/lib/img/nav/buttonAOn.gif"; buttonA_off.src = "/lib/img/nav/buttonAOff.gif";
  buttonB_on.src = "/lib/img/nav/buttonBOn.gif"; buttonB_off.src = "/lib/img/nav/buttonBOff.gif";
  buttonC_on.src = "/lib/img/nav/buttonCOn.gif"; buttonC_off.src = "/lib/img/nav/buttonCOff.gif";
  buttonD_on.src = "/lib/img/nav/buttonDOn.gif"; buttonD_off.src = "/lib/img/nav/buttonDOff.gif";
  buttonE_on.src = "/lib/img/nav/buttonEOn.gif"; buttonE_off.src = "/lib/img/nav/buttonEOff.gif";
  buttonF_on.src = "/lib/img/nav/buttonFOn.gif"; buttonF_off.src = "/lib/img/nav/buttonFOff.gif";
	
}

// rollover functions

function on(imageName) {
        if (document.images) document[imageName].src = eval(imageName + "_on.src");
}

function off(imageName) {
        if (document.images) document[imageName].src = eval(imageName + "_off.src");
}