<form name="myform" method="get" action="process.php">
  <datalist id="mydata">
    <option value="123123123" label="Phone 1">
    <option value="456456456" label="Phone 2">
  </datalist>
  <p><label>Phone: <input type="tel" name="myphone" list="mydata"></label></p>
  <p><input type="submit" value="Send"></p>
</form>