A PHP paging program, error, How to solve

A PHP paging program, error
This is the paging program:

PHP Code

  Include_once (' conn.php '), if (Isset ($_get[' Pclass ')) {$p _class=$_get[' pclass '];} else {$p _class= ';} $respage = mysql_query ("Select COUNT (*) from product where p_class= ' $p _class ';"); $num is the total number of qualifying records in the datasheet while ($row = Mysql_fetch_assoc ($respage)) {$num = $row [0];//This line error: notice:undefined offset:   0 in D:\setup\xampp\htdocs\products\showclass.php on line $recordnum = 40; How many records are displayed per page, $pages = ceil ($num/$recordnum); How many pages are there if (@$_get["page"])//Gets the parameters in the URL page {//$pre and $next The value of the page for the connection parameters of the previous and subsequent pages//AS           The parameter in the URL is 1, the current page is set to 1 previous page, $pre is one, $next is 2 if ($_get["page"]==1) {$current = 1;//Current page    $pre = 1;   $pre is the $next of the previous page = 2;           $next is the next page} else {$current = $_get["page"];           $pre = $current-1;           $next = $current +1;    }//If the parameter in the URL is not one (not the first page), the current page is evaluated to the parameter obtained in the URL, $pre minus 1 for the current page, $next to add 1} else      {$current = 1;           $pre = ' 1 ';          $next = 2;        }//If there is no parameter page in the URL, the current page is 1, $pre =1, $next =2 $now = ($current-1) * $RECORDNUM; $echopage = "
  
  
      "; $echopage. = " 
     "; $echopage. = " 
     ";//Error: notice:undefined index:hp_self in D:\setup\xampp\htdocs\products\showclass.php on line $echopage. =" 
     ";//Error: notice:undefined index:hp_self in D:\setup\xampp\htdocs\products\showclass.php on line $echopage. =" 
     "; $echopage. = " 
    

 
   
   
 
    
". $pages." Page
First page
 
     
Last page
Previous page Next page
to the first\ n "; for ($i =1; $i <= $pages; $i + +) {if ($i = = $current) $echopage. = "$i \ n "; else $echopage. = "$i \ n "; } $echopage. = "Page
 
   

  
  
";

Here's the code that needs to be paged:

PHP Code

===== on the Web side error:

notice:undefined offset:0 in D:\setup\xampp\htdocs\products\showclass.php on line 88

notice:undefined index:hp_self in D:\setup\xampp\htdocs\products\showclass.php on line 120

notice:undefined index:hp_self in D:\setup\xampp\htdocs\products\showclass.php on line 120

notice:undefined index:hp_self in D:\setup\xampp\htdocs\products\showclass.php on line 121


------Solution--------------------
$num = $row [0];//This line error
is because MYSQL_FETCH_ASSOC returns an associative array with no subscript
Change to Mysql_fetch_array

The hp_self should be php_self

