diff --git a/ui-lib.pl b/ui-lib.pl
index 4aee5c658..62fbb9ee8 100755
--- a/ui-lib.pl
+++ b/ui-lib.pl
@@ -659,6 +659,14 @@ if ($buttons && @$buttons) {
 	$rv .= "</tr></table>\n";
 	}
 $rv .= "</form>\n";
+# When going back to a form, re-enable any text fields generated by
+# ui_opt_textbox that aren't in the default state.
+$rv .= "<script>\n";
+$rv .= "var opts = document.getElementsByClassName('ui_opt_textbox');\n";
+$rv .= "for(var i=0; i<opts.length; i++) {\n";
+$rv .= "  opts[i].disabled = document.getElementsByName(opts[i].name+'_def')[0].checked;\n";
+$rv .= "}\n";
+$rv .= "</script>\n";
 return $rv;
 }
 
@@ -1230,7 +1238,6 @@ $rv .= "<input class='ui_opt_textbox' name=\"".&quote_escape($name)."\" ".
        ($max ? " maxlength=$max" : "").
        " ".$tags.
        ">\n";
-$rv .= "<script>if ($ui_formcount < document.forms.length) { document.forms[$ui_formcount].$name.disabled = document.forms[$ui_formcount].${name}_def[0].checked; }</script>\n";
 return $rv;
 }