--- /dev/null
+<form name="foo">
+<input type=text name=user>
+<input type=text name=foo>
+<input type=hidden name=bar value=1>
+</form>
+
+
+<script>
+document.validation="\n\
+ user:\n\
+ required: 1\n\
+ foo: {required_if: 'bar'}\n\
+";
+</script>