plz find the error
it give this error
Warning: Cannot modify header information - headers already sent by (output started at D:\xampp\htdocs\soomrof\a_task_2_1.php:3) in D:\xampp\htdocs\soomrof\a_task_2_1.php on line 24

<?
include("connection.php");
 
$check=false;
 
$sql=mysql_query("select * from doctor_schedule_information where  doctor_ID='".$_POST[doctor_id]."'") or die(mysql_error());
 
if(mysql_num_rows($sql)==1)
{
$row=mysql_fetch_array($sql);
$check=true;
}
 
else
 
{
$check=false;
}
 
if($check==true)
{
header("location:a_task_2_3.php");
}
else
{
header("location:a_task_2.php");
}
 
 
 
 
?>

I will recommend you post the content of that file.

I mean the codes in the connection.php file

connection.php

<?

$cn=mysql_connect("localhost","root");
mysql_select_db("dummy",$cn);


?>