order: reset objectrowid on contact_id change

entity/Order_entity/entityfields/contact_id/onValueChange.js

+import("system.neon");
 import("system.vars");
 import("system.db");
 import("Util_lib");
@@ -8,5 +9,7 @@ if(contactid != "")
 {
     var relData = db.array(db.ROW, "select ISOLANGUAGE from CONTACT where CONTACTID = '" + contactid + "'");
     
-    if(relData[0] != "")    vars.set("$field.ISOLANGUAGE", relData[0]);
-}
\ No newline at end of file
+    if(relData[0] != "")   
+        vars.set("$field.ISOLANGUAGE", relData[0]);
+}
+neon.setFieldValue("$field.OBJECT_ROWID", null)
\ No newline at end of file