Visual Basic

App.PrevInstance

Dim conn  As New ADODB.Connection
Dim adors As New ADODB.Recordset
Dim sql   As String

sql = "SELECT User_ID Where username = '" & replace(txtUserName.Text, "'", "''") & "'"

Set conn  = New ADODB.Connection
Set adors = New ADODB.Recordset

conn.ConnectionString = <code>"[YourConnectionStringGoesHere]"</code>
conn.Open
adors.ActiveConnection = conn
adors.Open (sql)
If Not adors.EOF Then
   Do Until adors.EOF
       MsgBox txtUserName.Text & "'s user id is " & adors("User_ID")
       adors.MoveNext
   Loop
Else
   MsgBox "There are no records that match that name"
End If

adors.Close
Set adors = Nothing
conn.Close
Set conn = Nothing