Okay, try the following steps, just for testing...
- Create a new blank form
- In Design View, add a Textbox (let's assume it's name is Text0)
- In the Properties Window of the form, find the Timer Interval property and enter 1000 (1 sec)
- In the On Timer property, select [Event Procedure] from the dropdown
- Click on the three dots next to [Event Procedure] to open the code window
- Enter the following code: If Me.Text0.BackColor=vbYellow Then
Me.Text0.BackColor=vbWhite
Else
Me.Text0.BackColor=vbYellow
End If
- View the form in Normal View
Hope that helps...