--- a/backend.py	Thu Apr 26 19:26:19 2018 +0200
+++ b/backend.py	Wed Aug 29 23:53:10 2018 +0200
@@ -1,4 +1,4 @@
-# 2.5.6 backend
+# 2.5.8 backend
 
 # written by VB.
 
@@ -232,6 +232,8 @@
 
     def addValue(self, parm, value):
         if type(value) is str or type(value) is unicode:
+            if value[0] != "'" and value[0] != '"':
+                value = "'" + value + "'"
             self.values[parm] = u(evalPython(value))
         else:
             self.values[parm] = u(evalPython(u(value)))