JSFiddle - React, Tailwind, and code Playground

HTML

<table>
  <tr id="date">
    <td class="left" valign="top">
      <label>Some content: </label>
    </td>
    <td class="right">
      <input type="button" name="submit5" onclick="goodFunctionName()" class="btn" value="Tarih ekle" />
    </td>
  </tr>
  <tr id="ek_takvim">
    <td class="left" valign="top">
      Yo!!
    </td>
    <td class="right">   
    </td>
  </tr> 
</table>

CSS

#ek_takvim { display: none; }

JavaScript

function goodFunctionName(){
  $("#ek_takvim").show();
  $("input[name=submit5]").hide();	
}