User X Only Can View Information X?

I have the FormLogin, which have the code:

Dim OLE As String = "SELECT * FROM Utilizadores WHERE [Username] = @Username and [Password] = @Password"
Dim myConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source='" & My.Application.Info.DirectoryPath & "BD.mdb';Persist Security Info=True;"
Dim connection As New OleDbConnection(myConnectionString)

[code].....

When I enter on the program, I Register the Username 1. I type the information on the Textboxs Form Login and I enter to the Form Information.In the Form Information, i type some information on the textboxs, Save and I get out.Enter the program again, Register another Username 2, Type information on the Textboxs Form Login and I enter to the Form Information, and I see the Information that I typed on the Username 1..and here's the problem...how can i fix it?