function overImage(imgId, overImg) {
	document.outImg = document.getElementById(imgId).src;
	document.getElementById(imgId).src = overImg;
	if (document.getElementById(imgId).parentNode.className=="naviButton") {
		document.getElementById(imgId).parentNode.className="naviButton_ov";
	}
}
function outImage(imgId) {
	document.getElementById(imgId).src = document.outImg;
	if (document.getElementById(imgId).parentNode.className=="naviButton_ov") {
		document.getElementById(imgId).parentNode.className="naviButton";
	}
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}