Convert raise statements in Tools/.
diff --git a/Tools/modulator/varsubst.py b/Tools/modulator/varsubst.py
index 3b33950..473fb55 100644
--- a/Tools/modulator/varsubst.py
+++ b/Tools/modulator/varsubst.py
@@ -29,7 +29,7 @@
                 continue
             name = m.group(1)
             if not self.dict.has_key(name):
-                raise error, 'No such variable: '+name
+                raise error('No such variable: '+name)
             value = self.dict[name]
             if self.do_useindent and '\n' in value:
                 value = self._modindent(value, rv)