I have a table for Sites, which includes name and type, among other fields.
I have a Asset transaction table which links Assets to Members (Custodians) and Sites, to provide historical status information about assets.
The Asset Transaction form includes a combo box to select a member as Custodian, a combo box to select a Site and control to display the Site Type from the Sites table, among other controls.
As it is now, the sub-form, under Assets, requires me to select a site, or it reports Site_ID cannot be found (when none has been selected). It is the Site_Type control, which is causing this error.
I need the Site_Type display control to retrieve the Site_Type data from the Site table, only when the Site Combo box has selected a Site, in which case, both the [Site] Combo box and the [Site_ID] will have a value.
After several different attempts to tell the Site_Type control not to retrieve data when a site has not been selected, I cannot figure out how to do this.
The Sites.Site_Type happens to be combo box to select Types for Sites. Since the control in this context is for display only, I have it disabled. I also tried using a simple text field to display the site type, but, of course it still attempts to retrieve data when no site has been selected.
The two controls in the sub-form are highlighted.