I have a set of check boxes in an Access mdb file. The mdb fle is linked to a set of tables in an SQL Express 2005 database. Bit datatypes have caused all sorts of issues, so I have to use tinyint. However, if I try to put a tick in a checkbox I get "Value Entered isn't valid for this Field". This would appear to be because Access treats a tick as a -1, and of course tinyint fields can only accept 0 to 255. Is there a way of making the value of a tick in access +1 instead of -1?