Structure Details
        Dim custID, lastName, firstName, add1, add2, state, city, email As String
        Dim icNo, zip, mobile, home, office As String
    End Structure
    Dim id(27) As Details
    Private Sub search_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim sr As IO.StreamReader = IO.File.OpenText("d:\data\cust.txt")
        For i As Integer = 0 To 27
            id(i).custID = sr.ReadLine
            id(i).icNo = sr.ReadLine
            id(i).lastName = sr.ReadLine
            id(i).firstName = sr.ReadLine
            id(i).add1 = sr.ReadLine
            id(i).add2 = sr.ReadLine
            id(i).zip = sr.ReadLine
            id(i).state = sr.ReadLine
            id(i).city = sr.ReadLine
            id(i).office = sr.ReadLine
            id(i).mobile = sr.ReadLine
            id(i).home = sr.ReadLine
            id(i).email = sr.ReadLine
        Next
        sr.Close()

    End Sub

    Private Sub btnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSearch.Click

        Dim searchID As String, result As String
        searchID = txt_searchID.Text.ToUpper
        result = FindID(searchID)
        If result >= 0 Then
            ShowData(result)
        Else
            MsgBox(searchID & " not in file", 0, "Not Found")
        End If

        
    End Sub

    Function FindID(ByVal searchID As String) As Integer
        'Binary search table for customer id
        Dim first, middle, last As Integer
        first = 0
        last = 27
        Do While (first <= last)
            middle = CInt(Int((first + last) / 2))
            Select Case id(middle).custID.ToUpper
                Case searchID
                    Return middle
                Case Is > searchID
                    last = middle - 1
                Case Is < searchID
                    first = middle + 1
            End Select
        Loop
        Return -1
    End Function

    Sub ShowData(ByVal result As Integer)
        txt_custID.Text = id(result).custID
        txt_icNo.Text = id(result).icNo
        txt_lastName.Text = id(result).lastName
        txt_1stName.Text = id(result).firstName
        txt_add1.Text = id(result).add1
        txt_add2.Text = id(result).add2
        txt_zip.Text = id(result).zip
        txt_state.Text = id(result).state
        txt_city.Text = id(result).city
        txt_office.Text = id(result).office
        txt_mobile.Text = id(result).mobile
        txt_home.Text = id(result).home
        txt_email.Text = id(result).email
    End Sub

Dim searchID As String, result As String

Dim searchID As String, result As Integer