i = 1; timer = 0;
function flip(back){
	if(!back){
		var newi = i + 1; 
		if(newi == 4) newi = 1;
	} else {
		var newi = i - 1; 
		if(newi == 0) newi = 3;		
	}	
	//$("#gallery_" + i).hide("slow", function(){$("#gallery_" + newi).show("slow");});
	$("#gallery_" + i).fadeOut("slow", function(){$("#gallery_" + newi).fadeIn("slow");});
	i = newi;
	timer = -100;
}

function checktimer(){
	timer = timer + 1;
	if(timer > 10) flip();
}

$(document).ready(function(){	
	window.setInterval('checktimer()', 1000);
});