Hi,

Try something like this:

- Select the BindingNavigator and use the properties window to set
DeleteItem to (none).

- Double click on the delete button and add this code:

private void bindingNavigatorDeleteItem_Click(object sender, EventArgs e)
{
 // cancel any pending new row
 // (only has effect for ADO.NET or Custom Objects with IEditableObject)
 int count = someBindingSource.Count;
 someBindingSource.CancelEdit();
 someBindingSource.ResetBindings(false);

 // if no pending new row was removed, remove current row
 if (someBindingSource.Count == count)
   someBindingSource.RemoveCurrent();
}

- Add a CurrentChanged or CurrentItemChanged to the relevant BindingSource:

private void someBindingSource_CurrentChanged(object sender, EventArgs e)
{
 CustomObject obj = (CustomObject)someBindingSource.Current;

 // warning, in VB.NET use AndAlso not And
 if (someBindingSource.Count > 0 && obj.SomeProp!=SomeCondition)
   bindingNavigatorDeleteItem.Enabled = true;
 else
   bindingNavigatorDeleteItem.Enabled = false;
}

HTH,
Greetings