rinnn

while (true)
{
    if (int1 > 20)
        {
            //код
        }   
    
    if (int2 > 400)
        {
            //код
        }

    if (int3 > 300)
        {
            //код
        }
   System.Threading.Thread.Sleep(200000);
}

if(DateTime.Now.Hour == 21)
            {
                MessageBox.Show("Test");
            }

<tr>
  <td class="rborder" align="center">1234</td>
  <td class="rborder" align="center">            
      Клубника
  </td>
</tr>

/tr/td[contains(., '1234')]/following-sibling::td/normalize-space(text())