var preloadFlag = false;
var imgName;              // nav btn over now
var thisPage;             // page loaded now
var mainNav;              // main nav btn now

function newImage(arg) {
  if (document.images) {
    rslt = new Image();
    rslt.src = arg;
    return rslt;
  }
}

function preloadImages(thisPage) {
  if (document.images && (preloadFlag == false)) {  // main nav preload
    btn1_0 = newImage("images/btn1_0.jpg");
    btn1_1 = newImage("images/btn1_1.jpg");
    btn2_0 = newImage("images/btn2_0.jpg");
    btn2_1 = newImage("images/btn2_1.jpg");
    btn3_0 = newImage("images/btn3_0.jpg");
    btn3_1 = newImage("images/btn3_1.jpg");
    btn4_0 = newImage("images/btn4_0.jpg");
    btn4_1 = newImage("images/btn4_1.jpg");
    //...
    preloadFlag = true;
    mainNav = thisPage;
    imgName = "btn"+mainNav;
    btn_over(imgName);
  }
  if (mainNav == 3) { // set default photo gallery category
    show('gallery3')
  }
 	window.status = "Chelan Closets - Custom Design & Manufacturing - phone 509.881.4730";
}

function changeImages() {
  if (document.images && (preloadFlag == true)) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
    }
  }
}

function btn_over(imgName) {  // main nav
  if (document.images && (preloadFlag == true)) {
		document[imgName].src = eval(imgName + "_1.src");
	} 
}

function btn_off(imgName) {
  if (document.images) {
		if ("btn"+mainNav != imgName) {
			document[imgName].src = eval(imgName + "_0.src");
		}
		else {
			document[imgName].src = eval(imgName + "_1.src");
		}
	}
}

function show(element) {
  if (document.getElementById) {
    document.getElementById(element).style.display = 'block';
  }
}

function hide(element) {
  if (document.getElementById) {
    document.getElementById(element).style.display = 'none';
  }
}