I'll have to update that with the mouse  control. I've just
let user  press 'd' to activate the Calendar.

Now I have another problem.
I'm calling frmCalendar.Show when the user enters the box and
press 'd', that will popup  the calendar  GUI... When I select the
date, it loads the date in to the textbox  and gives out an Run-time
error 400 Form already displayed; can't show modally.

There is two form. frmCalendar, frmVA. The frmVA is the main form
with all the textboxes. frmCalendar is the calendar popup.

Some snipet from the code  on frmVA:

Private Sub txtReferralDate_Change()
frmCalendar.Show
End Sub

Private Sub txtDOB_Change()
frmCalendar.Show
End Sub

Some snipet from the code on frmCalendar:
Private Sub Calendar1_Click()
If frmVA.txtReferralDate.Value = "d" Then
frmVA.txtReferralDate.Value = Calendar1.Value
End If

If frmVA.txtDOB.Value = "d" Then
frmVA.txtDOB.Value = Calendar1.Value
End If

Unload Me
End Sub