php form data to determine whether the POST come, judging data submission

1  // determine whether the POST form data from, determine the data submission 
2  IF ( $ _SERVER [ 'REQUEST_METHOD']! = 'POST' ) {
 3      // something non-POST antecedents, warning, or do you want to do 
4      return ;
 . 5 } the else {
 . 6      // the POST, do you want to do, POST processing request submitted by the user
 . 7      // header ( 'the Location: user.php and'); 
. 8 }