// preload level 1 buttons
var btnLevel1 = new Array();
btnLevel1 = ["overview", "difference", "services", "tour"];
for (var i = 0; i < btnLevel1.length; i++) { 
	eval("A" + i + "on = new Image();"); eval("A" + i + "off = new Image();");
	eval("A" + i + "on.src = \"img/btn-" + btnLevel1[i] + "-r.gif\";");
	eval("A" + i + "off.src = \"img/btn-" + btnLevel1[i] + "-0.gif\";");
}

// preload bottom buttons
var btnLevel2 = new Array();
btnLevel2 = ["learn-surgery", "find-physician"];
for (var i = 0; i < btnLevel2.length; i++) { 
	eval("B" + i + "on = new Image();"); eval("B" + i + "off = new Image();");
	eval("B" + i + "on.src = \"img/btn-" + btnLevel2[i] + "-r.jpg\";");
	eval("B" + i + "off.src = \"img/btn-" + btnLevel2[i] + "-0.jpg\";");
}

// preload constant buttons
var btnLevel7 = new Array();
btnLevel7 = ["home", "contact"];
for (var i = 0; i < btnLevel7.length; i++) { 
	eval("C" + i + "on = new Image();"); eval("C" + i + "off = new Image();");
	eval("C" + i + "on.src = \"img/cnst-" + btnLevel7[i] + "-r.gif\";");
	eval("C" + i + "off.src = \"img/cnst-" + btnLevel7[i] + "-0.gif\";");
}

// Image Swapping
function changeImages() 
{
  if (document.getElementById) {
    for (var i = 0; i < changeImages.arguments.length; i += 2) { 
  		document.getElementById(changeImages.arguments[i]).src = eval(changeImages.arguments[i + 1] + ".src"); 
	}
  }
}