How does "Execution Order" in PHP code function?

[Skyrider]

Already mentioned that in my post at the bottom:

to prevent any other usergroups being moved other than the one I selected.

yadacodehere

I included a code to prevent that second in overriding it.

Part of the first code:

$dataman =& datamanager_init('User', $vbulletin, ERRTYPE_STANDARD);
$dataman->set_existing($vbulletin->userinfo); 

if xxxxxx AND $vbulletin->userinfo['usergroupid'] == 13)

{
$dataman->set('usergroupid', 47);
$dataman->save();
}

Second code:

$dataman =& datamanager_init('User', $vbulletin, ERRTYPE_STANDARD);
$dataman->set_existing($vbulletin->userinfo); 

if xxxx AND $vbulletin->userinfo['usergroupid'] == 13)

{
$dataman->set('usergroupid', 37);
$dataman->save();
}

As you can see, both has an IF check if the user is in usergroup 13, and the second code moves the user to that usergroup.. Now, unless I did something wrong with the coding here.. the second code should not override the first one at all. As I mentioned in my post above, separately they work as a charm. (one disabled, other enabled, and the other way around).