好 帮你啦

有没有 先。。。 Adodc1.ConnectionString 。。。。啊。。。。

建议1. 不要用 + 来连接字符串
2. 你只验证密码，不验证ID 啊？

楼主，我把myuser类和mydb类发给你，你自己修改下就应该可以了：
myuser：
'1 UserName Varchar 40 用户名
'2 Pwd Varchar 40 密码
'3 RK TinyInt 用户类型
'（0 - 系统默认用户）
Public UserId As String
Public UserName As String
Public UPass As String
Public UPrav As String
Public UQx As String
'*********************************************
Public Sub Init()
UserId = ""
UserName = ""
UPrav = ""
UQx = ""
End Sub
'**********************************************
'删除UserInfo数据
Public Sub Delete(ByVal TmpUser As String)
If TmpUser = "1" Then
Kk = MsgBox("超级用户不准许删除", vbOKOnly, "警告")
Exit Sub
End If
Mydb.openDB
SqlStmt = "DELETE FROM UserInfo WHERE UserId='" _
+ Trim(TmpUser) + "'"
Dim Isexe As Boolean
Dim rsUser As ADODB.Recordset
Isexe = Mydb.exeSql(SqlStmt, rsUser, True)
Mydb.closeDB
End Sub
'**************************************************************
'获取UserInfo数据库信息
Public Function GetInfo(ByVal TmpUser As String) As Boolean
Dim TUserGd As Variant
If TmpUser = "" Then
Init
GetInfo = False
Exit Function
End If
UserName = TmpUser
'打开数据库
Mydb.openDB
SqlStmt = "SELECT * FROM UserInfo WHERE UserName='" _
+ Trim(TmpUser) + "'"
Dim Isexe As Boolean
Dim rsUser As ADODB.Recordset
Isexe = Mydb.exeSql(SqlStmt, rsUser, True)
'判断用户是否在数据库里，如果没有，则GetInfo=0
'否则读取用户信息和用户类型、权限
If rsUser.EOF Then

GetInfo = False
Mydb.closeDB
Exit Function
Else

UserId = rsUser.Fields("UserId")
UserName = rsUser.Fields("UserName")

If IsNull(rsUser.Fields("UPass")) = False Then
UPass = rsUser.Fields("UPass")
Else
UPass = ""
End If
UQx = rsUser.Fields("UQx")
UPrav = rsUser.Fields("UPrav")
GetInfo = True
Mydb.closeDB
End If
End Function
'**********************************************
Public Function GetNewId() As Long
Dim TmpId As Long
Mydb.openDB
SqlStmt = "Select UserId from UserInfo Order by UserId"
Dim Isexe As Boolean
Dim rsUser As ADODB.Recordset
Isexe = Mydb.exeSql(SqlStmt, rsUser, True)
i = 1
Do While rsUser.EOF = False
TmpId = rsUser.Fields("UserId")
If TmpId = i Then
i = i + 1
Else
GetNewId = i
Mydb.closeDB
Exit Function
End If
rsUser.MoveNext
Loop
Mydb.closeDB
GetNewId = i
End Function
'**************************************************************
'插入UserInfo信息
Public Sub Insert()
User_Id = GetNewId
Mydb.openDB
SqlStmt = "INSERT INTO UserInfo Values('" & Trim(str(User_Id)) & "'," _
+ "'" & Trim(UserName) & "','" & Trim(UPass) & "'," _
+ "'" & Trim(UPrav) & "'," _
+ "'" & Trim(UQx) & ")"
Dim Isexe As Boolean
Dim rsUser As ADODB.Recordset
Isexe = Mydb.exeSql(SqlStmt, rsUser, True)
Mydb.closeDB
End Sub
'**************************************************************
'更新UserInfo信息
Public Sub Update(ByVal TmpUser As String)
If Trim(TmpUser) = "Admin" Then
Kk = MsgBox("超级用户不准许修改", vbOKOnly, "警告")
Exit Sub
End If
Mydb.openDB
SqlStmt = "Update UserInfo Set UserName ='" + Trim(UserName) + "'" _
+ ",UPass='" + Trim(CStr(UPass)) + "'" _
+ ",UPrav='" + Trim(CStr(UPrav)) + "'" _
+ ",UQx='" + Trim(CStr(UQx)) + "'" _
+ " WHERE UserName='" + Trim(TmpUser) + "'"
Dim Isexe As Boolean
Dim rsUser As ADODB.Recordset
Isexe = Mydb.exeSql(SqlStmt, rsUser, True)
Mydb.closeDB
End Sub

mydb类：
Option Explicit
Private Const CONN_STRING As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source="
Public DB_PATH As String
'数据库连接
Public dbConn As New ADODB.Connection
'表明当前数据库的连接状态:False－未连接；True－已连接
Public dbStatus As Boolean
Public Function openDB() As Boolean
'DB_PATH = dbPath
'dbConn.Open CONN_STRING & DB_PATH
'MsgBox Err.Description
Dim connString As String
connString = "Provider=SQLOLEDB.1;User ID=sa;pwd=y69m10d17;Initial Catalog=Northwind;Data Source= hostlocal ;"
dbConn.Open "Provider=SQLOLEDB.1;User ID=sa;pwd=y69m10d17;Initial Catalog=Northwind;Data Source= hostlocal ;"
If err.Number <> 0 Then MsgBox err.Description: GoTo errHandler
'dbStatus = True
openDB = True
Exit Function
errHandler:
openDB = False
MsgBox ("数据库连接失败，请与系统管理员联系！")
End Function
Public Function closeDB() As Integer
dbConn.Close
'xxx
dbStatus = False
End Function
Public Function exeSql(sqlStr As String, queryResult As ADODB.Recordset, Optional enableWrite As Boolean = True) As Boolean
On Error GoTo errHandler:
Dim ret
Set queryResult = New ADODB.Recordset
If enableWrite Then
queryResult.Open sqlStr, dbConn, adOpenStatic, adLockOptimistic
Else
queryResult.Open sqlStr, dbConn, adOpenStatic, adLockReadOnly
End If
exeSql = True
Exit Function
errHandler:
MsgBox err.Description
exeSql = False
Exit Function
End Function