When you say the textbox isn't editable, why isn't it? Have you set the
Enabled or Locked property of the textbox to prevent editing or is it's
Control Source not editable? If the Control Source isn't editable, then
you'll have to fix the Control Source, probably a query, to make it
editable. However, if you've set the Enable and/or Locked properties for the
textbox to prevent users from editing it, then that can be changed when a
selection is made in the listbox.
If the MultiSelect property of the listbox is set to None:
In the AfterUpdate event of the listbox, check to see if the Value is Null,
if not, then enable the textbox.
Example:
If IsNull(Me.lstMyListbox) Then
Me.txtMyTextbox.Enabled = False
Me.txtMyTextbox.Locked = True
Else
Me.txtMyTextbox.Enabled = True
Me.txtMyTextbox.Locked = False
End If
Use the Enable and/or Locked properties in the code, depending on which of
these you've used to disable editing.
If the MultiSelect Property of the listbox is set to Simple or Extended:
In the AfterUpdate event of the listbox, check to see how many items are
selected. If one or more, then enable the textbox.
Example:
If Me.lstMyListbox.ItemsSelected.Count = 0 Then
Me.txtMyTextbox.Enabled = False
Me.txtMyTextbox.Locked = True
Else
Me.txtMyTextbox.Enabled = True
Me.txtMyTextbox.Locked = False
End If
You may also need to do this in the form's Current event.