function navi(){
	var bgImg = new Array("headerBg1.gif","headerBg2.gif","headerBg3.gif","headerBg4.gif","headerBg5.gif");
	var selectNum = Math.floor(Math.random() * bgImg.length);
	
	if((selectNum == 0) || (selectNum == 4)){
		
		if(document.all){
				document.all('subn1').style.color = "#ffffff";
				document.all('subn2').style.color = "#ffffff";
				document.all('naviarea').style.background = "#cccccc url(images/top/" + bgImg[selectNum] + ")";
		}
		if(document.getElementById){
				document.getElementById('subn1').style.color = "#ffffff";
				document.getElementById('subn2').style.color = "#ffffff";
				document.getElementById('naviarea').style.background = "#cccccc url(images/top/" + bgImg[selectNum] + ")";
		}
	
	}else{
		
		if(document.all){
				document.all('subn1').style.color = "#000000";
				document.all('subn2').style.color = "#000000";
				document.all('naviarea').style.background = "#cccccc url(images/top/" + bgImg[selectNum] + ")";
		}
		if(document.getElementById){
				document.getElementById('subn1').style.color = "#000000";
				document.getElementById('subn2').style.color = "#000000";
				document.getElementById('naviarea').style.background = "#cccccc url(images/top/" + bgImg[selectNum] + ")";
		}
	}
	
}