var browser = false;
  browser = document.images;

        var loaded = 0;

  // set up variables
  if (browser) initImages();

  // set up and pre-load all mouseOver images
  function initImages() {


    nav_bt10 = new Image(69,33);
  	nav_bt10.src = 'images/home.0.gif';
    nav_bt11 = new Image(69,33);
    nav_bt11.src = 'images/home.1.gif';

    nav_bt20 = new Image(219,33);
  	nav_bt20.src = 'images/classes.0.gif';
    nav_bt21 = new Image(219,33);
    nav_bt21.src = 'images/classes.1.gif';
    
    nav_bt30 = new Image(151,33);
  	nav_bt30.src = 'images/book.0.gif';
    nav_bt31 = new Image(151,33);
    nav_bt31.src = 'images/book.1.gif';

    nav_bt40 = new Image(111,33);
  	nav_bt40.src = 'images/contact.0.gif';
    nav_bt41 = new Image(111,33);
    nav_bt41.src = 'images/contact.1.gif'; 
    
    nav_bt50 = new Image(114,33);
  	nav_bt50.src = 'images/about.0.gif';
    nav_bt51 = new Image(114,33);
    nav_bt51.src = 'images/about.1.gif';
     
    nav_bt60 = new Image(114,33);
  	nav_bt60.src = 'images/digs.0.gif';
    nav_bt61 = new Image(114,33);
    nav_bt61.src = 'images/digs.1.gif';
               
		loaded = 1;

		// var ArrowOn = 1;
    }
	
  // turn the inages ON
  function overRunImg(imgName)  {
    if (browser) {
      x = eval("nav_" + imgName + "1.src");
      // y = eval("over_" + imgName + ".src");
      eval("document.nav_" + imgName + ".src = x");
      // eval("document.over.src = y");
      }
    }

  // turn the inages OFF
  function outRunImg(imgName)  {
    if (browser) {
      a = eval("nav_" + imgName + "0.src");
      // b = eval("over_default.src");
      eval("document.nav_" + imgName + ".src = a");
      // eval("document.over.src = b");
      }
    }