function chgsrc(){
	var sphoto;
	var a = document.getElementById("topphoto");
	if (a != null){
		tcount += 1;
		if (tcount > tmax) {
			tcount = 1;}
		sphoto = "photos/" + tpic[tcount-1];
		a.src = sphoto;
	}
	var b = document.getElementById("botphoto");
	if (b != null){
		bcount += 1;
		if (bcount > bmax) {
			bcount = 1;}
		sphoto = "photos/" + bpic[bcount-1];
		b.src = sphoto;
	}	
}
function settimer(){
	if (tmax > 1){
		var a = document.getElementById("topphoto");
		if (a != null){
			var ti = window.setInterval("chgsrc()",4000);}
	}
	if (bmax > 1){
		var b = document.getElementById("botphoto");
		if (b != null){
			var bi = window.setInterval("chgsrc()",4000);}
	}
}