Added ajax request to projections.json for hot swapping projector rotation

www/projections.json

@@ -0,0 +1,5 @@
+[
+  "scoreboard.html",
+  "tanks.html",
+  "credits.html"
+]

www/projector.html

@@ -20,10 +20,20 @@
       }
     </style>
 		<script>
-var urls = ["scoreboard.html", "credits.html", "tanks.html"];
+var SECS = 1000;
+var urls = ["scoreboard.html"];
 var stack = [];
-var secs = 1000;
 var i = 0;
+var xmlhttp;
+if (window.XMLHttpRequest){
+	xmlhttp = new XMLHttpRequest();
+}
+xmlhttp.onreadystatechange = function(){
+	if (xmlhttp.readyState == 4 && xmlhttp.status == 200){
+		urls = JSON.parse(xmlhttp.responseText);
+		//console.log("new urls:", urls);
+	}
+}
 function reload() {
   // alternate between scoreboard and other things
 	if (i%2){
@@ -31,15 +41,24 @@ function reload() {
 	}
 	else {
 		if (stack.length === 0){
+			xmlhttp.open("GET", "projections.json", true);
+			xmlhttp.send();
+			if (urls.length > 1){
 				stack = urls.slice(1);
 			}
+			else {
+				stack = urls;
+			}
+		}
 		url = stack.pop();
 	}
+	console.log("loading " + url + " of " + urls);
 	document.getElementById("reloader").src = url;
+	i++;
 }
 
 function init() {
-	setInterval(reload, 60*secs);
+	setInterval(reload, 2*SECS);
 }
 
 window.addEventListener("load", init);