Problem with selectionchangecommited of combobox

Private Sub cmbGroupName_SelectionChangeCommitted(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmbGroupName.SelectionChangeCommitted
MessageBox.Show(cmbGroupName.Text)

Dim da As New SqlDataAdapter()
Dim ds As New DataSet()
Try
da = New SqlDataAdapter("select item_id,item_name from items where group_name like '" + cmbGroupName.Text + "' and status like 'Active'", cl.sqlConn())
da.Fill(ds, "items")
cmbItemName.DataSource = ds.Tables("items")
cmbItemName.ValueMember = "item_id"
cmbItemName.DisplayMember = "item_name"
cmbItemName.SelectedIndex = -1

Catch ex As Exception
MessageBox.Show("Couldnot load Item name", "Error")
Finally
da.Dispose()
ds.Dispose()
End Try

End Sub

I have 2 combobox cmbgroupname and cmbitemname. both from mssql database is populated...on selecting groupname ,,,itemname is populated for that groupname. Im using vb2008


I executed above code in this ..first time when a group name is selected from dropdown ..then in above event it gives empty message then again display text...i.e on first time selection cmbitemname doest have data but if i again select same group name then cmbitemname has data. Is there any problem in my coding ? Im uisng above event bcoz i want to fill itemname only when user selects item in groupname.

Plz help

You might like to follow the CodeBank link in my signature and check out my thread on Master/Detail Data-Binding. Unless you have a large amount of data in the child table, that's the easiest option.