--- a/lib/js/urweb.js	Thu May 21 10:18:20 2009 -0400
+++ b/lib/js/urweb.js	Thu May 21 10:34:56 2009 -0400
@@ -295,12 +295,12 @@
   populate(x);
 }
 
-function input(t, s) {
+function input(t, s, recreate) {
   var x = document.createElement(t);
   x.dead = false;
   x.signal = ss(s);
   x.sources = null;
-  x.recreate = function(v) { if (x.value != v) x.value = v; };
+  x.recreate = recreate(x);
   populate(x);
   addNode(x);
 
@@ -308,7 +308,7 @@
 }
 
 function inp(s) {
-  var x = input("input", s);
+  var x = input("input", s, function(x) { return function(v) { if (x.value != v) x.value = v; }; });
   x.value = s.data;
   x.onkeyup = function() { sv(s, x.value) };
 
@@ -316,7 +316,7 @@
 }
 
 function sel(s, content) {
-  var x = input("select", s);
+  var x = input("select", s, function(x) { return function(v) { if (x.value != v) x.value = v; }; });
   x.innerHTML = content;
   x.value = s.data;
   x.onchange = function() { sv(s, x.value) };
@@ -324,6 +324,15 @@
   return x;
 }
 
+function chk(s) {
+  var x = input("input", s, function(x) { return function(v) { if (x.checked != v) x.checked = v; }; });
+  x.type = "checkbox";
+  x.checked = s.data;
+  x.onchange = function() { sv(s, x.checked) };
+
+  return x;
+}
+
 function addOnChange(x, f) {
   var old = x.onchange;
   x.onchange = function() { old(); f (); };