请问我写的这个php函数体传递变量的时候为什么总是上一个函数体的值？

<?phpsession_start();require("inc/pdo.php");//矫正时区差异ini_set("date.timezone","Asia/Chongqing");$time=date("Y-m-d H:i:s");//获得客户端ip$user_ip = $_SERVER["REMOTE_ADDR"];$name=$_POST["name"];$password=$_POST["password"];emptyloginnull($name,$password);//判断传值是否为空function emptyloginnull($name,$password){$functionName='';$functionName="emptyloginnull";if(!empty($name)&&!empty($password)){//都不是空...loginSQL($name,$password);}else{ 	echo Msg($functionName);	}}function loginSQL($name,$password){	$functionName='';$functionName=1;global $dbc;$md5PD=md5($b64=base64_encode($password));$selectUser=$dbc->prepare("select name,password,loginnumber,loginstatus from nasdaouser where name=? and password=?");$selectUser->execute(array($name,$md5PD));$userNum=$selectUser->rowCount();$res=$selectUser->fetch();if($userNum==1){  loginSuecess($name,$res,$md5PD);		}else {			Msg($functionName);	}}//登录成功function loginSuecess($name,$res,$md5PD){$functionName='';$functionName=0;global $dbc,$user_ip,$time;$loginlog=$dbc->prepare("insert into loginlog (name,password,ip,logintime,status,loginstatus) values(?,?,?,?,?,?)");$loginlog->execute(array($name,$md5PD,$user_ip,$time,'0','0'));$userLogin=$dbc->prepare("update nasdaouser set endlogintime=? where name=?");$userLogin->execute(array($time,$name));Msg($functionName);}function Msg($functionName){	echo $functionName; switch($functionName){	 case "emptyloginnull":	echo "不要调戏我好吗?系统也会数数的,你根本没有输入帐号与密码!!!";	 break;     case 0:	echo "登录成功!";	 break;	 case 1:	echo "登录失败,请检查帐号密码是否输入错误!";	}}?>

function Msg($functionName){  print_r(debug_backtrace()); //观察一下是谁调用的、参数是什么  switch($functionName){    .....  }}

function Msg($functionName){  print_r(debug_backtrace()); //观察一下是谁调用的、参数是什么  switch($functionName){    .....  }}

Array ( [0] => Array ( [file] => C:\wamp\www\mjshu\login.php [line] => 40 [function] => Msg [args] => Array ( [0] => 1 ) ) [1] => Array ( [file] => C:\wamp\www\mjshu\login.php [line] => 19 [function] => loginSQL [args] => Array ( [0] => smj227227 [1] => Password ) ) [2] => Array ( [file] => C:\wamp\www\mjshu\login.php [line] => 11 [function] => emptyloginnull [args] => Array ( [0] => smj227227 [1] => Password ) ) ) 登录失败,请检查帐号密码是否输入错误!

function Msg($functionName){  print_r(debug_backtrace()); //观察一下是谁调用的、参数是什么  switch($functionName){    .....  }}

Array ( [0] => Array (   [file] => C:\wamp\www\mjshu\login.php   [line] => 52   [function] => Msg   [args] => Array (     [0] => 0   ) ) [1] => Array (   [file] => C:\wamp\www\mjshu\login.php   [line] => 35   [function] => loginSuecess   [args] => Array (     [0] => smj227227     [1] => Array (       [name] => smj227227       [0] => smj227227       [password] => b9f94ff142c0d6da23543e4e37e04ac9       [1] => b9f94ff142c0d6da23543e4e37e04ac9       [loginnumber] =>       [2] =>        [loginstatus] => 0       [3] => 0     )     [2] => b9f94ff142c0d6da23543e4e37e04ac9   ) ) [2] => Array (   [file] => C:\wamp\www\mjshu\login.php   [line] => 19   [function] => loginSQL   [args] => Array (     [0] => smj227227     [1] => 227227   ) ) [3] => Array (   [file] => C:\wamp\www\mjshu\login.php   [line] => 11   [function] => emptyloginnull   [args] => Array (     [0] => smj227227     [1] => 227227   ) ))

var_dump(0 == "emptyloginnull");

var_dump(0 == "emptyloginnull");