How would I make an admin only download page in php?

<?php     // Include the database file or connect to mySQL and select dabase here     include('database.php');      // Your SQL query     $sql = "Select * from table_name ";     $result = mysql_query($sql);     $sep = "\t"; //tabbed character     // Mention your filename and path where you have to store that excel file    $fp = fopen('../file_name.xls', "w");    $schema_insert = "";    $schema_insert_rows = "";     for ($i = 0; $i < mysql_num_fields($result); $i++)     {         $schema_insert_rows.=mysql_field_name($result,$i) . "\t";     }         $schema_insert_rows.="\n";         fwrite($fp, $schema_insert_rows);     //start while loop to get data     while($row = mysql_fetch_row($result))     {     //set_time_limit(60); //         $schema_insert = "";     for($j=0; $j<mysql_num_fields($result);$j++)     {         if(!isset($row[$j]))             $schema_insert .= "NULL".$sep;         elseif ($row[$j] != "")             $schema_insert .= strip_tags("$row[$j]").$sep;         else             $schema_insert .= "".$sep;     }     $schema_insert = str_replace($sep."$", "", $schema_insert);         //this corrects output in excel when table fields contain \n or \r        //these two characters are now replaced with a space             $schema_insert = preg_replace("/\r\n|\n\r|\n|\r/", " ", $schema_insert);         $schema_insert .= "\n";     //$schema_insert = (trim($schema_insert));     //print $schema_insert .= "\n";     //print "\n";             fwrite($fp, $schema_insert);     } fclose($fp); // Code here will allow you to download the the excel file of your database $filename = '../file_name.xls'; $ctype="application/[extension]"; // required for IE, otherwise Content-disposition is ignored if(ini_get('zlib.output_compression')) ini_set('zlib.output_compression', 'Off'); header("Pragma: public"); // required header("Expires: 0"); header("Cache-Control: must-revalidate, post-check=0, pre-check=0"); header("Cache-Control: private",false); // required for certain browsers header("Content-Type: $ctype"); // change, added quotes to allow spaces in filenames header("Content-Disposition: attachment; filename=\"".basename($filename)."\";" ); header("Content-Transfer-Encoding: binary"); header("Content-Length: ".filesize($filename)); readfile("$filename"); exit(); ?>