Craig,

>I have a standard business maintenance form, in here I have a single control that is bound to a different business object, how do I get the form to recognise changes to this second object if the form is being closed for example?

If you register the second business object as a child of the form's primary business object, it will automatically detect changes in both. For example:

this.oOrder.RegisterChildBizObj(this.oOrderDetail);

Best Regards,