How to return populated gridview from a web service call

Hi, appreciate your help in the 2nd method inside web service, the .DataBind() cause error. not sure why, thanks public void GetAll2() // this work inside aspx page { SqlDataAdapter dad = new SqlDataAdapter("SELECT lastname,firstname,address, city, state, zipcode phonenumber FROM customers", _connectionString); SqlCommandBuilder builder = new SqlCommandBuilder(dad); DataTable dtblMovies = new DataTable(); dad.Fill(dtblMovies); GridView1.DataSource = dtblMovies; GridView1.DataBind(); Response.Write("DS"); } [WebMethod] public void GetCustomerGv() // I tried to use the same method to get gridview from a web service, does not work.... { SqlDataAdapter dad = new SqlDataAdapter("SELECT lastname,firstname,address, city, state, zipcode phonenumber FROM customers", _connec ...