hi guys i have a windows form on it has a username text field, password text field,a button and a label. When the user enters their password and username their employee ID number should appear on the label. The code i have is shown below, the problem is basically when i enter a username and password which is in the database i still get message saying incorrect login!

Imports System
Imports System.Data
Imports System.Data.OleDb
Imports System.Data.SqlClient
Imports System.Data.SqlTypes
Imports System.Diagnostics
Imports System.ComponentModel


Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.
    'Do not modify it using the code editor.
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents username As System.Windows.Forms.Label
    Friend WithEvents Password As System.Windows.Forms.Label
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Label1 As System.Windows.Forms.Label
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox()
        Me.TextBox2 = New System.Windows.Forms.TextBox()
        Me.username = New System.Windows.Forms.Label()
        Me.Password = New System.Windows.Forms.Label()
        Me.Button1 = New System.Windows.Forms.Button()
        Me.Label1 = New System.Windows.Forms.Label()
        Me.SuspendLayout()
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(120, 24)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(104, 20)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = ""
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(120, 56)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.Size = New System.Drawing.Size(104, 20)
        Me.TextBox2.TabIndex = 1
        Me.TextBox2.Text = ""
        '
        'username
        '
        Me.username.Location = New System.Drawing.Point(8, 24)
        Me.username.Name = "username"
        Me.username.Size = New System.Drawing.Size(96, 16)
        Me.username.TabIndex = 2
        Me.username.Text = "Username"
        '
        'Password
        '
        Me.Password.Location = New System.Drawing.Point(16, 56)
        Me.Password.Name = "Password"
        Me.Password.Size = New System.Drawing.Size(96, 16)
        Me.Password.TabIndex = 3
        Me.Password.Text = "password"
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(192, 192)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(88, 32)
        Me.Button1.TabIndex = 4
        Me.Button1.Text = "login in"
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(24, 264)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(96, 24)
        Me.Label1.TabIndex = 5
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(368, 309)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Label1, Me.Button1, Me.Password, Me.username, Me.TextBox2, Me.TextBox1})
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim varUser_Name As String
        Dim varPassword As String
        Dim varemployeeId As Int16
        Dim LoginSuccess As String
        Dim oConn As SqlConnection = New SqlConnection()
        Dim oTable As DataTable = New DataTable()
        Dim oRow As DataRow
        varUser_Name = TextBox1.Text
        varPassword = TextBox2.Text

        Try
            oConn.ConnectionString = "server=D401L11J;" _
            & "database=HumanResources;" _
            & "userId=sa;Password=manutd;"
            oConn.Open()
            Dim oDA As SqlDataAdapter = New SqlDataAdapter("select employeeId from userTable where (username ='" & TextBox1.Text & "' and password = '" & TextBox2.Text & "'", oConn)
            oDA.Fill(oTable)
            oConn.Close()

            For Each oRow In oTable.Rows
                varemployeeId = CInt(oRow("employeeid"))
            Next
        Catch ex As Exception

            Debug.WriteLine(ex.Message & ": " & ex.StackTrace)

            Label1.Text = varemployeeId
            If varemployeeId = 0 Then
                LoginSuccess = False
                MsgBox("Incorrect Login.", MsgBoxStyle.OKOnly, "Login Error")
                TextBox1.Text = ""
                TextBox2.Text = ""
                TextBox1.Focus()
            Else
                LoginSuccess = True
            End If

I hope you changed the server name/ system admin username and password before showing it here - I think displaying the real ones on the internet is a bad idea.

Your code looks ok, so what I'd suggest is using SQL Query Analyser to make sure that your query is ok. To get the closest match, step through the code and once the query is built, cut and paste it into query analyser and run it - see what you get back. Use query analyser to modify the query if it's not quite right, then change your code.

Is it the missing closing bracket in the SQL string?