How to use Static method in 3 tier Architecture

Question

Hi,
Can someone guide me how to Split this below static webmethod into 3 tier architecture? (DAL, BAL and UI)

[WebMethod]

public static string[] GetCustomers(string prefix)

{

List<string> customers = new List<string>();

using (SqlConnection conn = new SqlConnection())

{

conn.ConnectionString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;

using (SqlCommand cmd = new SqlCommand())

{

cmd.CommandText = "select ContactName, CustomerId from Customers where ContactName like @SearchText + '%'";

cmd.Parameters.AddWithValue("@SearchText", prefix);

cmd.Connection = conn;

conn.Open();

using (SqlDataReader sdr = cmd.ExecuteReader())

{

while (sdr.Read())

{

customers.Add(string.Format("{0}-{1}", sdr["ContactName"], sdr["CustomerId"]));

}

}

conn.Close();

}

}

return customers.ToArray();

}