var currentTime = new Date();
var futureTime = new Date();
var oneDay=1000*60*60*24;

futureTime.setFullYear(2012, 4, 12);
var diff = Math.round((futureTime.getTime() - currentTime.getTime())/(oneDay));

var str = String(diff);
if (str.length == 1)
	str = "00" + str; 
else if (str.length == 2)
	str = "0" + str;

document.getElementById('first_digit').src = "images/" + str.substr(0,1) + ".jpg";
document.getElementById('second_digit').src = "images/" + str.substr(1,1) + ".jpg";
document.getElementById('third_digit').src = "images/" + str.substr(2,1) + ".jpg";