Hola,
si tubieramos 3 formularios
form1, form2, form3
un combobox (ComboBox1)
Código PHP:
Public Class Form1
Dim frm02 As New Form2()
Dim frm03 As New Form3()
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
ComboBox1.Items.Add("Formulario 2")
ComboBox1.Items.Add("Formulario 3")
End Sub
Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
Select Case ComboBox1.SelectedIndex
Case 0
frm02.Show()
Case 1
frm03.Show()
Case Else
MsgBox("error")
End Select
End Sub
End Class