PHP page jump after session is empty

Generate Session Loginok.php

 
  '; Echo ' Click to go to Homepage '; Exit ();} else{echo ' Landing failed! Click Back '; }?>

[code=php
Judging index.php

Reply to discussion (solution)

Re-send it, it's messed up.
Generate Session Loginok.php

 
  ' Echo ' clicks into homepage '; exit ();} Else{echo ' Landing failed! Click Back to ';}? >

Judging index.php

!--? php session_start (); Var_dump ($_session[' userid "); if (! isset ($_session[') UserID ']) {echo "Login registration";}  else{$username =$_session[' username '];echo $username. ", Welcome to Logout"; Echo $_session[' userid ']; echo "Login Registration";}  
 Two files are placed in the same directory after logging in loginok.php generated session but jump to index.php, anyway, only display login registration 
 
 
 what browser test, Multiple browser tests to see.  
 
 IE and Sogou are not available 
 
 Firefox and Chrome can not 
 
 
 