why "header" does not work in my code?

[sarah89]

hello ^^


i used header in my codes, and it was working fine in the local server. but when i upload it to the public server i keep get the following error:

Warning: Cannot modify header information - headers already sent by (output started at /home/movc/public_html/dbconnector.php:23) in /home/movc/public_html/loginaction.php on line 31


in dbconnector.php :
i connect to the server and i never used header there!

and in loginaction.php i used:
[code] include_once("dbconnector.php"); [/DODE]

and this is the part of my code that i used header in:

 
    //Check whether the query was successful or not
    if($result) {
        header('location: welcome_msg1.php');
exit();}
    else
    header('location: erorr_msg1.php');
exit(); 
 

can you please tell me where i did wrong?
thanks so much ^^

[Dormilich]

it’s like the error messages says, 8 lines before you set the header, you have output, which causes the response body to begin and which renders any more headers invalid.

[sarah89]

thank you so much ^^ :*

but, what kind of error?
i review the code many times and couldn't find it!

if you can help me more and see the code:

//Create query
 
    $qry="SELECT * FROM user WHERE username='"$un"' AND pw='"$pw"';";
    $result=mysql_query($qry);
 
    //Check whether the query was successful or not
    if($result) {
    if(mysql_num_rows($result) == 1) {
            //Login Successful
 
            $member = mysql_fetch_assoc($result);
            $_SESSION['uid'] = $member['u_id'];
 
            header("location: controlpanel.php");
 
            exit();
        }else {
            //Login failed
            header("location: index.php");
 
            exit();
        }
    }else {
        die("Query failed");
    }
 
 

[Dormilich]

that kind of error:

Warning: Cannot modify header information - headers already sent by (output started at /home/movc/public_htm/dbconnector.php:23) in /home/movc/public_html/loginaction.php on line 31

[sarah89]

^^
i mean the error in the code!
what i should change in my code to make this error msg stop!!

[Dormilich]

remove the output before the header() call.