try this:

Code:
Imports System.Data.SqlClient

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim conn As New SqlConnection("connection string")
        Dim cmd As New SqlCommand("SELECT [Name] FROM employee WHERE employeeID=@employeeID", conn)
        'which of these 2 parameters you use depends on employeeID field datatype
        cmd.Parameters.Add("@employeeID", SqlDbType.Int).Value = CInt(textbox1.text)
        'cmd.Parameters.Add("@employeeID", SqlDbType.VarChar).Value = textbox1.text
        Dim o As Object = cmd.ExecuteScalar
        TextBox2.text = If(o IsNot Nothing, o.ToString, "")
    End Sub
End Class