title: Where is my mistake in my written php code if all are works finely?
body: <p>**Look at the picture **</p>
  
  <p><a href="https://i.stack.imgur.com/9GZJl.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9GZJl.jpg" alt="enter image description here"></a></p>
  
  <p>I want to see the page without <em>'Notice:'</em> because here all the result I think works finely. But why does it shows. Any Mistake? Please help me.</p>
  
  <p><strong>The code is like:</strong></p>
  
  <pre><code>&lt;?php
      mysql_connect("localhost","root");
      mysql_select_db("simple");
      $id=$_POST['id'];
      $res=mysql_query("SELECT * FROM simple_tb WHERE id=$id");
      while($row=mysql_fetch_array($res))
      {
  ?&gt;
      &lt;link rel="stylesheet" type="text/css" href="demo.css" media="screen" /&gt;&lt;/head&gt;
      &lt;h1 align="center"&gt; ABC IDEAL SCHOOL AND COLLEGE&lt;/h1&gt;
      &lt;h3 align="center"&gt;Baraiyahat, Chittagong, 01772969874 &lt;/h3&gt;
      &lt;p align="center"&gt;Students Tuetion Fee Payment Sheet&lt;br&gt;&lt;/p&gt;
      &lt;table class="table" align="center"width="800"  bgcolor="skyblue"&gt;
          &lt;tr&gt;&lt;td width="25%"&gt;ID No:&lt;/td&gt;&lt;td width="25%"&gt;&lt;?php echo $row['id'];?&gt;&lt;/td&gt;&lt;/tr&gt;
          &lt;tr&gt;&lt;td&gt;Name:&lt;/td&gt; &lt;td&gt;&lt;?php echo $row['n'];?&gt;&lt;/td&gt;&lt;/tr&gt;
          &lt;tr&gt;&lt;td&gt;Class:&lt;/td&gt;&lt;td&gt;&lt;?php echo $row['c'];?&gt;&lt;/td&gt;&lt;/tr&gt;
          &lt;tr&gt;&lt;td&gt;Roll:&lt;/td&gt; &lt;td&gt;&lt;?php echo $row['r'];?&gt;&lt;/td&gt;&lt;/td&gt;&lt;/tr&gt;
      &lt;/table&gt;
      &lt;br&gt;
      &lt;h4 ALIGN="CENTER"&gt;PAYMENT STATUS&lt;/H4&gt;
          &lt;table align="center"width="800" BORDER="1" bgcolor="red"&gt;
              &lt;tr&gt;
                  &lt;td align="center"&gt;&lt;B&gt;DATES&lt;/B&gt;&lt;/td&gt;
                  &lt;td align="center"&gt;&lt;B&gt;DESCRIPTION&lt;/B&gt;&lt;/td&gt;
                  &lt;td align="center"&gt;&lt;B&gt;MEMO NO&lt;/B&gt;&lt;/td&gt;
                  &lt;td align="center"&gt;&lt;B&gt;BDT&lt;/B&gt;&lt;/td&gt;
                  &lt;td align="center"&gt;&lt;B&gt;Con.Total&lt;/B&gt;&lt;/td&gt;
              &lt;/tr&gt;
  &lt;?php
  
          $res2=mysql_query("SELECT * FROM ac WHERE sid=".$row['id']);
          while($row2=mysql_fetch_array($res2))
          {   $sum+= $row2['t'];
          ?&gt;
  
              &lt;tr bgcolor="cream"&gt;
                  &lt;td bgcolor="white"align="center"&gt;&lt;?php echo $row2['d'];?&gt;&lt;/td&gt;
                  &lt;td bgcolor="white"align="center"&gt;&lt;?php echo $row2['des'];?&gt;&lt;/td&gt;
                  &lt;td bgcolor="white"align="center"&gt;&lt;?php echo $row2['m'];?&gt;&lt;/td&gt; 
                  &lt;td bgcolor="white"align="center"&gt;&lt;?php echo $row2['t'];?&gt;&lt;/td&gt;
                  &lt;td bgcolor="white"align="center"&gt;&lt;?php echo $sum."&lt;br&gt;";?&gt;&lt;/td&gt;
                   &lt;td bgcolor="white"align="center"&gt;&lt;/td&gt;
              &lt;/tr&gt;
  
  &lt;?php
          }
          ?&gt;&lt;/table&gt;&lt;?php
      }
  </code></pre>
  
  <p><em>Now please tell me details what can I do for the written code.</em></p>