Yes i dragged it from the field list. Does it make a difference that it is in
a subform rather than a form? how do I know if it is bound to the table? and
locked and enabled?
The sub form is a form. If you dragged the check box from the Field
list onto the sub-form, then it is bound to the field in the table
unless someone 'unbound' it.
In that sub form's Form Design View right-click on the check box
control. Select Properties. Click on the Data tab. The Control Source
should indicate the name of the field to which to check box is bound.
If the control source is blank, click on the drop-down arrow on that
line and select the correct field.
The Enabled property should read Yes.
The Locked property should read No.
By the way, you still haven't said what 'does not work' means.
Perhaps your form or subform is set to Read Only or Allow Edits No.