kaiser,
try looking at this code by Malcolm...it deals with comboboxes but the principle is the same..it disables the continue button until fields are completed. Hope this helps get you started in the right direction and if you have more problems post back.
Be sure you rename the buttons etc in the code as it has not been changed in any way to fit your file. just an example I thought would give you some tips.
[VBA]
Private Sub Userform_Initialize()
ComboBox1.AddItem ("Joe")
ComboBox2.AddItem ("is")
ComboBox3.AddItem ("cool.")
CommandButton1.Enabled = False
End Sub
Private Sub CommandButton2_Click()
Me.Hide
End Sub
Private Sub ComboBox1_Change()
SetButton
End Sub
Private Sub ComboBox2_Change()
SetButton
End Sub
Private Sub ComboBox3_Change()
SetButton
End Sub
Private Sub SetButton()
If ComboBox1.Value <> "" And ComboBox2.Value <> "" And ComboBox3.Value <> "" Then
CommandButton1.Enabled = True
Else
CommandButton1.Enabled = False
End If
End Sub
[/VBA]