how to make a drop down list which responds to the letter you enter in html :     <!DOCTYPE html>
    <html>
    <head>
    <meta charset="UTF-8">
    <title>choose a country</title>
    </head>
    <body>
    <h1>Where would you like to go?</h1>
    <form action="some.jsp">
      <select name="item">
        <option value="america">America</option>
        <option value="turkey">Turkey</option>
        <option value="brazil">France</option>
        <option value ="spain">Spain</option>
        <option value ="Egypt">Egypt</option>
        <option value ="Dubai">Dubai</option>
        <option value = Argentina">Argentina </option>
        <option value = "canada"> Canada </option>
        <option value = "france">France</option>
      </select>
      <input type="submit" value="lets go!!">
     </form>
    </body>
    </html>


I want to make a drop list in which when you press the letter A then all the countries with the letter A pop up. Im confused on how to do this 
also I want to align this to the centre of the page. How would I go about this.