setcookie statements are giving me error

I'm trying to set multiple cookies and getting the error below. I removed all of the white spaces and extra lines before and after my <?php and ?>, so, that shouldn't be an issue. I get the error for each cookie and it echoes back as "...cookie not set" like I coded. This is the code chunk I'm trying to run, which is called using "require ("setcookie.php");" from my main script. There aren't any extra spaces in my main script because I can replace the require line with "header ('Location: http://www.anything.com');" and it will redirect successfully without any cannot modify header errors, which tells me there's nothing wrong with my main script. Am I doing something wrong with cookies here? "Warning: Cannot modify header information - headers already sent by....." setcookie ("acctActive_ck", "$daysRemaining"); //set cookie for active account, will terminate when browser window closes if (setcookie("acctActive_ck")) { echo "active cookie set"; } else { echo "active cookie not set";} setcookie ("login_ck", "$lo"); //set cookie for active account, will terminate when browser window closes if (setcookie("login_ck")) { echo "login cookie set"; } else { echo "login cookie not set";} setcookie ("password_ck", "$pw"); //set cookie for password, will terminate when browser window closes if (setcookie("password_ck")) { echo "pw cookie set"; } else { echo "pw cookie not set";} Thanks a million, Ryan