Login Form VB.NET 01

Dim MyDS As New DataSet
     Dim conns As String = "Data Source=ISAAC;Initial Catalog=SETH;Integrated Security=True"
     Dim Conn As New SqlConnection
     Conn.ConnectionString = conns

     Dim Cmd As SqlDataAdapter
     Cmd = New SqlDataAdapter("select * from login where username='" & Trim(C1TextBox1.Text) & "' and password='" & TRIM(C1TextBox2.Text)& "'", Conn)

     Cmd.Fill(MyDS, "login")
     Dim table As DataTable = MyDS.Tables("login")
     Dim i As Integer
     Dim j As Integer
    if ( table.Rows.Count= 1)
          Form1.Show()
         Me.Close()

Else
         MsgBox("Incorrect Login")
         C1TextBox1.Focus()
     End If

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As a side note:
You sql statement is susceptible to SQL
injection. Unless you are doing some sort of sanitizing on your textbox
input, you should consider using 

parameters in your queries.

For instance, if I were to type
x' or 1 = 1; --
in your textbox, I have just bypassed your login procedure (because 1 = 1 will always evaluate true and thus return all rows).
You should use command parameters as demonstrated in the snippet.

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        Dim adapter As System.Data.SqlClient.SqlDataAdapter
     Dim cmd As New System.Data.SqlClient.SqlCommand("Select * from login where username = @user and password = @pass")

     cmd.Parameters.Add(New System.Data.SqlClient.SqlParameter("@user", ClTextBox1.Text.Trim()))
     cmd.Parameters.Add(New System.Data.SqlClient.SqlParameter("@pass", ClTextBox2.Text.Trim()))

     adapter = New System.Data.SqlClient.SqlDataAdapter(cmd)
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