--- a/lib/js/urweb.js	Thu Sep 24 07:52:57 2009 -0400
+++ b/lib/js/urweb.js	Thu Sep 24 10:42:59 2009 -0400
@@ -618,7 +618,8 @@
   xhr.send(null);
 }
 
-function rc(uri, parse, k, needsSig) {
+function rc(prefix, uri, parse, k, needsSig) {
+  uri = cat(prefix, uri);
   uri = flattenLocal(uri);
   var xhr = getXHR();
 
@@ -790,6 +791,10 @@
   }
 }
 
+function sl(ms, k) {
+  window.setTimeout(function() { execF(k, null); }, ms);
+}
+
 
 // Key events
 
@@ -854,9 +859,6 @@
   var stack = null;
 
   while (true) {
-    if (!e.c)
-      throw ("Trace: " + trace);
-    trace += "|" + e.c;
     switch (e.c) {
     case "c":
       var v = e.v;
@@ -879,6 +881,7 @@
           e = {c: "c", v: fr.f.apply(null, fr.args)};
           stack = stack.next;
         } else {
+          trace += "" + fr.pos;
           e = fr.a.data;
           fr.a = fr.a.next;
         }
@@ -891,7 +894,7 @@
         if (fr.f == null)
           throw "Ur: applying null function";
         else if (fr.f.body) {
-          stack = cons({c: "a3", env: env}, stack.next);
+          stack = cons({c: "<", env: env}, stack.next);
           env = cons(v, fr.f.env);
           e = fr.f.body;
         } else {
@@ -899,7 +902,7 @@
           stack = stack.next;
         }
         break;
-      case "a3":
+      case "<":
         env = fr.env;
         stack = stack.next;
         break;
@@ -923,7 +926,7 @@
         stack = stack.next;
         break;
       case "=":
-        stack = cons({c: "a3", env: env}, stack.next);
+        stack = cons({c: "<", env: env}, stack.next);
         env = cons(v, env);
         e = fr.e2;
         break;
@@ -932,7 +935,7 @@
         for (ps = fr.p; ps != null; ps = ps.next) {
           var r = execP(env, ps.data.p, v);
           if (r != false) {
-            stack = cons({c: "a3", env: env}, stack.next);
+            stack = cons({c: "<", env: env}, stack.next);
             env = r;
             e = ps.data.b;
             break;