Autogenerate serial number in textbox

[vkk49]

hi
i want to generate serial number in text box when i click on button.so please help me

[prashantsb]

if use random function or if use database then fire to select query & get last record id or number , add it one and then display textbox.

[vkk49]

thanks for the reply.
i have the following code that generate serial number,but problem is that if i save 4 serial numbers and i delete serial number 3 and when i click to generate new serial number then its show 5 and 3 is missing.do you have any solution for this?

Dim dr As OleDbDataReader
        Dim a As Integer
        If Not cn.State = ConnectionState.Open Then
            cn.Open()
        End If
        sqlqry = "select srno from Records"
        cmd = New OleDbCommand(sqlqry, cn)
        dr = cmd.ExecuteReader
        While dr.Read
            a = dr(0)
        End While

        Dim i As Integer

        If Integer.TryParse(CStr(CDbl(a) + 1), i) Then
            TextBox1.Text = i.ToString
        End If