var nlength=5;
var n=new Array(nlength);
	n[0]="classic";
	n[1]="genesis";
	n[2]="megadrive";
	n[3]="saturn";
	n[4]="sega";

function randomLogo(themeName){
	var randomIndex=Math.floor(Math.random()*nlength);

	document.write("<img border='0' src='images/logos/logo-");
	document.write(n[randomIndex]);
	document.write("_");
	document.write(themeName);
	document.write(".gif'>");
}