//
// this file contains code used by the menu bar (menu.htm)
// it is also used by other pages when linking in order to
// allow the menu to change properly
//

var maxmenu = 12;

var imgOn = new Array(maxmenu);
var imgOff = new Array(maxmenu);

var currButtonNum = -1;

//
// initialization code
//
for (var i=0; i < maxmenu; i++) {
  imgOn[i] = new Image();
  imgOff[i] = new Image();
  imgOn[i].src = 'images/fret' + eval(i) + 'a.jpg'
  imgOff[i].src = 'images/fret' + eval(i) + '.jpg'

}


// set the menu image to the "on" (on mouseover)
function setImageOn(imgNum) {
	if ((document.images) && (imgNum!=currButtonNum)) {
    document.images['fret' + imgNum].src = imgOn[imgNum].src;
  }  
}

// set the menu image to the "off" (on mouseout)
function setImageOff(imgNum) {
	if ((document.images) && (imgNum != currButtonNum)) {
   document.images['fret' + imgNum].src = imgOff[imgNum].src;
  } 
}

// set the menu image to the "selected" image (onclick)
function setImageSel(imgNum) {
  if (document.images != null) {
    document['fret' + currButtonNum].src = imgOff[currButtonNum-1].src;
    currButtonNum = imgNum;
    document['fret' + imgNum].src = imgOn[imgNum].src;
	}
}




// set the menu image to the "selected" image only if required
// called by child pages to check for menu sync when page is selected
// independently of menu, via back button or page-to-page internal link
function setImageSelIfNeeded(imgNum) {
  if ((currButtonNum != imgNum) || (imgNum == 1)) {
    setImageSel(imgNum);
  } 
}