header failing conditions

[d40sithui]

Hi all,
I have a shopping cart that I designed by myself (yay) that uses session to store items. After you put items in the cart, you can hit "checkout" and it'll take you to the "shipping information form." A few people are complaining that when they hit the "Submit" button on this form, they get a "blank screen" (empty script). The form action points to a script that validates posted data and uses the header() function at the very end to redirect back to the main page, printing out any errors or displaying the "review information" page. The script is in a different folder than the main index. It works fine on my pc, as well as other PCs at home that I've tried on. Even if you access the script directly, it will still redirect automatically. So my question is, can there anything else in play that can cause the header() function to not execute or somehow display this "blank screen"? I've only been in the PHP business for a little over a year so my experience is limited. Perhaps someone can shed some light into this matter. Thanks.

-khanh

[coopster]

You are likely sending something out to the browser prior to the redirect. Did you check your error log?

[d40sithui]

Thanks for the reply,
I don't have an error log =/. Or at least I can't find it where it usually would be. But the thing is, it works fine on my PC at work and at home. So idk, i thought it would be something else rather than the you know output before header(). I scanned the file, no echo or print statements.
Here is the script for reference.

/*
inializing PN
this is needed to preserv PN SESSION variables
*/
ini_set('include_path',ini_get('include_path').':../:'); //sets to main dir since pnAPI.php will include other files too.
if(!include ("includes/pnAPI.php")){
die("Error code 1: Failed to load core file");
}
pnInit();
if(!include("includes/inc.php")){
die("Error code 2: Failed to load core file");
}
/*
prevents inclusion
*/
if(includedScript("orderformProcessCheckout.php")){
die("Please don't include me.");
}
/*
if cart is set->continue
*/
if(isset($_SESSION['orderformShoppingCart'])){
/*
retrieving variables
*/
$orderformFirstName = mysql_less_safe(clean_var($_POST['orderformFirstName']));
$orderformLastName = mysql_less_safe(clean_var($_POST['orderformLastName']));
$orderformService = mysql_less_safe(clean_var($_POST['orderformService']));
$orderformTitlePosition = mysql_less_safe(clean_var($_POST['orderformTitlePosition']));
$orderformFacility = mysql_less_safe(clean_var($_POST['orderformFacility']));
$orderformAddress = mysql_less_safe(clean_var($_POST['orderformAddress']));
$orderformCity = mysql_less_safe(clean_var($_POST['orderformCity']));
$orderformState = mysql_less_safe(clean_var($_POST['orderformState']));
$orderformZip = mysql_less_safe(clean_var($_POST['orderformZip']));
$orderformCountry = mysql_less_safe(clean_var($_POST['orderformCountry']));
$orderformPhone = mysql_less_safe(clean_var($_POST['orderformPhone']));
$orderformEmail = mysql_less_safe(clean_var($_POST['orderformEmail']));
/*
checking variables
*/
$results = array(); //holds error
/*
first name
*/
if(validInputString($orderformFirstName) && strlen($orderformFirstName)>0){
$_SESSION['orderformFirstName'] = $orderformFirstName;
}
else{
unset($_SESSION['orderformFirstName']);
$results[] = "<div class=\"error\">First Name is empty or contains invalid characters</div>\n";
}
 
/*
last name
*/
if(validInputString($orderformLastName) && strlen(orderformLastName)>0){
$_SESSION['orderformLastName'] = $orderformLastName;
}
else{
unset($_SESSION['orderformLastName']);
$results[] = "<div class=\"error\">Last Name is empty or contains invalid characters</div>\n";
}

/*
service
*/
if(strcasecmp($orderformService, "AIR_FORCE")==0 ¦¦ strcasecmp($orderformService, "ARMY")==0 
¦¦ strasecmp($orderformService, "NAVY")==0 ¦¦ strcasecmp($orderformService, "other")==0){
$_SESSION['orderformService'] = $orderformService;
}
else{
unset($_SESSION['orderformService']);
$results[] = "<div class=\"error\">Service is invalid</div>\n";
}
/*
title/position
*/
if(validInputString($orderformTitlePosition) && strlen($orderformTitlePosition) > 0){
$_SESSION['orderformTitlePosition'] = $orderformTitlePosition;
}
else{
unset($_SESSION['orderformTitlePosition']);
$results[] = "<div class=\"error\">Title/Position is empty or contains invalid characters</div>\n";
}

/*
facility
*/
if(validInputString($orderformFacility) && strlen($orderformFacility) > 0){
$_SESSION['orderformFacility'] = $orderformFacility;
}
else{
unset($_SESSION['orderformFacility']);
$results[] = "<div class=\"error\">Facility is empty or contains invalid characters</div>\n";
}

/*
Address
*/
if(validInputString($orderformAddress) && strlen($orderformAddress) > 0){
$_SESSION['orderformAddress'] = $orderformAddress;
}
else{
unset($_SESSION['orderformAddress']);
$results[] = "<div class=\"error\">Address is empty or contains invalid characters</div>\n";
}

/*
city
*/
if(validInputString($orderformCity) && strlen($orderformCity) > 0){
$_SESSION['orderformCity'] = $orderformCity;
}
else{
unset($_SESSION['orderformCity']);
$results[] = "<div class=\"error\">City is empty or contains invalid characters</div>\n";
}
/*
Zip
*/
if(validZip($orderformZip)){
$_SESSION['orderformZip'] = $orderformZip;
}
else{
unset($_SESSION['orderformZip']);
$results[] = "<div class=\"error\">Zip is not long enough or contains invalid characters</div>\n";
}
/*
state
*/
if(validInputString($orderformState) && strlen($orderformState) > 0){
$_SESSION['orderformState'] = $orderformState;
}
else{
unset($_SESSION['orderformState']);
$results[] = "<div class=\"error\">State is not long enough or contains invalid characters</div>\n";
}

/*
Country
*/
if(validInputString($orderformCountry) && strlen($orderformCountry) > 0){
$_SESSION['orderformCountry'] = $orderformCountry;
}
else{
unset($_SESSION['orderformCountry']);
$results[] = "<div class=\"error\">Country is empty or contains invalid characters</div>\n";
}
/*
phone
*/
if(validPhone($orderformPhone)){
$_SESSION['orderformPhone'] = $orderformPhone;
}
else{
unset($_SESSION['orderformPhone']);
$results[] = "<div class=\"error\">Phone is must be at least 10 digits and may only contain dashes and periods.</div>\n"; 
}
/*
email
*/
if(validEmail($orderformEmail) && validEmail2($orderformEmail)){
$_SESSION['orderformEmail'] = $orderformEmail;
}
else{
unset($_SESSION['orderformEmail']);
$results[] = "<div class=\"error\">Email is invalid.</div>\n";
}
/*
assigns results to session
*/
if(!empty($results[0])){
$_SESSION['results'] = $results;
}
}//ends if cart is set
/*
cart is not set -> disp. error
*/
else{
$_SESSION['results'] = "<div class=\"error\">Cart is not set.</div>\n";
}
header('Location: /index.php?name=psorderform&view=checkout');

[coopster]

As long as your secondary functions here (mysql_less_safe, clean_var, and your other validation routines) are not outputting any data or failing anywhere, it may be your header construction. Try building a complete 1.1 header, which is good practice anyway. See the header [php.net] manual pages for details.