DropDownList?

Why can't I select any items from my DropDownList(info_cmpycde)?

Private Sub info_cmpycde_SelectedIndexChanged
cmpy.text = info_cmpycde.SelectedItem.Value
or
cmpy.text = info_cmpycde.SelectedItem.Text
End Sub

*cmpy textbox is still null value

your sub needs to be

VB Code:

Private Sub info_cmpycde_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles info_cmpycde.SelectedIndexChanged
        cmpy.Text = info_cmpycde.SelectedItem.Value
 
    End Sub

if you want the textbox to be updated as soon as you click the drop down list you will also need to set the autopostback=true property of the drop down list