Answers for "javascript options in select"

make select option selected javascript

document.getElementById('personlist').getElementsByTagName('option')[11].selected = 'selected'

options in html

<form id="form">
            <label for=""></label>
            <br>
            <input type="" id="">
            <br>
            <label for=""></label>
            <br>
            <input list="browsers" name="Thenicknamey" id="Thenickname">
            <datalist id="browsers">
                <option value=""></option>
                <option value=""></option>
                <option value=""></option>
            </datalist>
            <br>
            <label for=""></label>
            <br>
            <input type="" id="">
            <br>
            <input type="" id="">
        </form>

js select option in form

<form name="AddAndEdit">
   <select name="list" id="personlist">
      <option value="P1">Person1</option>
      <option value="P2">Person2</option>
      <option value="P3">Person3</option>
   </select>
</form>