Feature Help - 50 Max Loss From 1 IP

I'm making a referrer system which will use credits to decide weather or not ads are displayed... If a user has credits, 1 credit is removed per impression and no ad is displayed... If they have no credits, then an ad is displayed... I'd like to make it where a single IP can only count for the loss of a max of 50 credits per day... I've made this much so far:

// Connect to database
$Database_Host = "********";
$Database_Name = "********";
$Database_Username = "********";
$Database_Password = "********";

$DBConn = mysql_connect($Database_Host, $Database_Username, $Database_Password) or die("Could not connect to database server. Check your settings...");
$DB_DB = mysql_select_db($Database_Name, $DBConn) or die("Could not connect to database ($Database_Name). Perhaps you don't have the right permissions on this DB. Check your settings...");


$query=mysql_query("SELECT adcredits FROM testing"); 
$query_row=mysql_fetch_array($query);


// Generate the ad space...
 if (($query_row[adcredits]) > 0){
	$subtracted = $query_row[adcredits] - 1; 
	$sql = mysql_query("UPDATE testing SET adcredits='$subtracted'"); // Update the database after subtraction
  echo "No ad will be displayed since they have credits... You have $subtracted left... "; 
 }
 else {
  echo "Ad is displayed since you have no credits... <BR>[the ad would go here]"; 
	$sql = mysql_query("UPDATE testing SET adcredits='0'"); // Ensure credit amount isin't a negative number...
 }

PHP:

Everything above works fine... But I'd like to add the feature mentioned above... Any ideas? I was thinking maybe cookies... But any working alternative will do fine...

Thanks...

 

I don`t know how could work if you set no username, but i will make the feature you wanted, i hope it works:

// Connect to database


$Database_Host = "********";

$Database_Name = "********";

$Database_Username = "********";

$Database_Password = "********";

 

$DBConn = mysql_connect($Database_Host, $Database_Username, $Database_Password) or die("Could not connect to database server. Check your settings...");

$DB_DB = mysql_select_db($Database_Name, $DBConn) or die("Could not connect to database ($Database_Name). Perhaps you don't have the right permissions on this DB. Check your settings...");

 
$query=mysql_query("SELECT adcredits FROM testing");

$query_row=mysql_fetch_array($query);



// Generate the ad space...

if(!isset($_COOKIE['visited']) || $_COOKIE['visited'] != 'yes') {

 if (($query_row[adcredits]) > 0){

    $subtracted = $query_row[adcredits] - 1;

    $sql = mysql_query("UPDATE testing SET adcredits='$subtracted'"); // Update the database after subtraction

  echo "No ad will be displayed since they have credits... You have $subtracted left... ";

 }

 else {

  echo "Ad is displayed since you have no credits... <BR>[the ad would go here]";

    $sql = mysql_query("UPDATE testing SET adcredits='0'"); // Ensure credit amount isin't a negative number...

 } 

setcookie('visited','yes',time() + (60*60*24));

}

PHP:

 

It gives this error:

Warning: Cannot modify header information - headers already sent by (output started at /home/michael/public_html/test/frontend.php:41) in /home/michael/public_html/test/frontend.php on line 47

 

I think that your setcookie should be before any other output so before the echo statements

 

Thanks! Works perfect now!!!

 

or you could put a simple <?php ob_start();?> on the first line of the script