我用VB做了一个登陆界面。。。连接SQL数据库，如何判断用户名密码，以下是代码，不知道哪里错了，帮改改



Dim strSQL As String
Dim cn As New ADODB.Connection
Dim rs As New ADODB.Recordset

Private Sub cmdEnter_Click()
If txtUser.Text = "" Then
MsgBox "请您输入用户名"
txtUser.SetFocus
Exit Sub
End If
If txtPwd.Text = "" Then
MsgBox "请您输入密码"
txtPwd.SetFocus
Exit Sub
End If
cn.ConnectionString = "driver={sql server};server=(local);database=userman;uid=sa;pwd=sa"
cn.Open

cn.CursorLocation = adUseClient

strSQL = "select * from users where userName='" & txtUser.Text & " ' and userPwd= ' " & txtPwd.Text & " '"

rs.Open strSQL, cn, adOpenStatic, adLockReadOnly
If rs.RecordCount = 0 Then
MsgBox "用户名不正确"
Else
If rs.Fields(0).Value = txtPwd.Text Then
MsgBox "登录成功"
Else
MsgBox "密码错误"

End If
End If

End Sub

Private Sub cmdExit_Click()
End
End Sub