C#

private void GetServerList()
{
    DataTable dt;

    // Set local server as default
    dt = SmoApplication.EnumAvailableSqlServers(false);
    if (dt.Rows.Count > 0)
    {
        // Load server names into combo box
        foreach (DataRow dr in dt.Rows)
        {
            ServerNamesComboBox.Items.Add(dr["Name"]);
        }

        // Default to this machine
        ServerNamesComboBox.SelectedIndex
            = ServerNamesComboBox.FindStringExact(
            System.Environment.MachineName);

        // If this machine is not a SQL server
        // then select the first server in the list
        if (ServerNamesComboBox.SelectedIndex < 0)
        {
            ServerNamesComboBox.SelectedIndex = 0;
        }
    }
    else
    {
        ExceptionMessageBox emb = new ExceptionMessageBox();
        emb.Text = Properties.Resources.NoSqlServers;
        emb.Show(this);
    }
}

// SMO namespaces
using Microsoft.SqlServer.Management.Common;
using Microsoft.SqlServer.Management.Smo;
using Microsoft.SqlServer;
using Microsoft.SqlServer.MessageBox;

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
  if(e.KeyChar == '^')
  {
    e.Handled = true;
  }
}

// Disable '%' key
case 52:

case 52:

private void textBox_KeyPress(object sender, KeyPressEventArgs e)
    {
    if (e.KeyChar == '^')
        {
        e.Handled = true;
        }
    }