JSFiddle - React, Tailwind, and code Playground

HTML

<select id="ddlSkills">
  <option value="C#">C#</option>
  <option value="ASPNET">ASP.NET</option>
  <option value="JQuery">JQuery</option>
  <option value="Others">其他</option>
</select>
<div style="display:none" id="divOthers">
    <textarea></textarea>
</div>

JavaScript

$('#ddlSkills').change(function(){
    if($(this).val() == 'Others') {
        sessionStorage.setItem('ShowOthers', "Y");
        $('#divOthers').show();
    }
    else {
        sessionStorage.setItem('ShowOthers', "N");
        $('#divOthers').hide();
    }
});

$(function(){ 
    //如果SessionStorage為Y時，秀出textarea
    if (sessionStorage.getItem("ShowOthers") == "Y") {
        $('#divOthers').show();
    }
});