diff -r b24c11c93766 -r 7f57b969caed plcopen/plcopen.py
--- a/plcopen/plcopen.py	Sun Mar 17 19:03:25 2013 +0100
+++ b/plcopen/plcopen.py	Wed Mar 20 23:47:07 2013 +0100
@@ -1383,7 +1383,7 @@
     setattr(cls, "removepouVar", removepouVar)
     
     def hasblock(self, name):
-        if self.getbodyType() in ["FBD", "LD", "SFC"]:
+        if name != "" and self.getbodyType() in ["FBD", "LD", "SFC"]:
             for instance in self.getinstances():
                 if isinstance(instance, PLCOpenClasses["fbdObjects_block"]) and instance.getinstanceName() == name:
                     return True