while ($row = mysql_fetch_assoc($query)){
echo("<tr id='$a' bgcolor='B0C4DE'>");
$sr_num=$row['b_sr_num'];
echo ('<td>'.$row['b_sr_num'].'</td>');
echo ('<td>'.$row['b_name'].'</td>');
echo ('<td>'.$row['b_author'].'</td>');
echo ('<td>'.$row['b_avail'].'</td>');
if($row['b_avail']>0)
{
if (!$_SESSION["valid_user"])
{
// User not logged in, redirect to login page
echo("<td>Available</td>");
}else
echo("<td><INPUT TYPE=button id=show name=show[] value=add onClick=buttonPress('$sr_num','$a')></td>");
can you give me the code of or sample to use next