Display a selected row?

[cturner01]

I need to display a selected id row from a query string in a textbox and just displayed by printing that row. The row originately comes from a database. Can someone please tell me how I can do this? Thanks in advance.
Here is the code that I am working with:

require "config.php";

// one SQL statement
$query= 'SELECT * FROM diary_contents WHERE `id` >=1 ORDER BY id LIMIT 0,1';

// one call to mysql_query
$r= mysql_query($query) OR die('Query error: ' .mysql_error());

// one call to fetch the resultset
$row= mysql_fetch_assoc($r);

// display the date info
echo $row['selectDay'].'-'.$row['selectMonth'].'-'.$row['selectYear'].'<br />';

// display the record data
echo '<textarea name="diary_entry" cols="30" rows="5" id="diary_entry">'.$row['diary_entry'].'</textarea>';

mysql_close(); 

[aamonkey]

  require "config.php";
  
  // find id (this assumes that the query string variable is named 'id':
  $id = $_GET['id'];
  
  // make sure id is a number, and safeguard against an sql injection
  if (!preg_match("#^\d+$#", $id)) {
      // maybe die here with an error
  }
  
  // one SQL statement
  $query= "SELECT * FROM diary_contents WHERE id = '$id'";
  
  // one call to mysql_query
  $r= mysql_query($query) OR die('Query error: ' .mysql_error());
  
  // make sure the entry was found
  if (mysql_num_rows($r) == 0) {
    // no entry with this id found, maybe die here with an error
  }
  
  // one call to fetch the resultset
  $row= mysql_fetch_assoc($r);
  
  // display the date info
  echo $row['selectDay'].'-'.$row['selectMonth'].'-'.$row['selectYear'].'<br />';
  
  // display the record data
  echo '<textarea name="diary_entry" cols="30" rows="5" id="diary_entry">'.$row['diary_entry'].'</textarea>';
  
  mysql_close();