Private Sub MLIB_Click()
Dim UserName As String
Dim PassWord As String

' MUN is the name of the textbox associated to the Username
' MPW is the name of the textbox associated to the Password
UserName = MUN.Value
PassWord = MPW.Value

If UserName = Application.WorksheetFunction.VLookup(UserName, Sheets("User_List").Range("B3:C1000"), 1, True) Then
    If PassWord = Application.WorksheetFunction.VLookup(PassWord, Sheets("User_List").Range("B3:C1000"), 2, True) Then
       Sheets("Home_Page").Activate
       Unload Me
    End If
End If
MsgBox "Sorry, Incorrect Login Details"
End Sub

With Worksheets("User_List")
    If Not IsError(Application.Match(UserName, .Column(2), 0)) Then
        If Password = Application.VLookup(UserName, .Range("B:C"), 2, False) Then
           Worksheets("Home_Page").Activate
           Unload Me
        End If
    End If
End With
MsgBox "Sorry, Incorrect Login Details"