data = new Array;

data[0]="/images/main_01-on.gif"
data[1]="/images/main_02-on.gif"
data[2]="/images/main_03-on.gif"
data[3]="/images/main_04-on.gif"
data[4]="/images/main_05-on.gif"
data[5]="/images/main_06-on.gif"
data[6]="/images/main_07-on.gif"

preload = new Array();
for(i=0; i<data.length; i++)
{
preload[i] = new Image();
preload[i].src = data[i];
}

function cngimg(n){
	var imgsrc = n.src;
	if(imgsrc.indexOf("jpg") <= 0){
		extension=".gif";
	}
	else{
		extension=".jpg";
	}

	if(imgsrc.indexOf("-on") <= 0){
		n.src=imgsrc.substring(0,imgsrc.length-4) +"-on"+extension;
	}
	else{
		n.src=imgsrc.substring(0,imgsrc.length-7) +extension;
	}
}