Hi,
there is one problem with <?=
This only works if short_open_tags is enabled in php.ini. If that option is disabled then <?=$avar; ?> will not work.
Also note that you'll run into problems if you have XML code in your script with short_open_tags enabled.
<?xml .... ?>
<?PHP
echo 'something';
?>
That causes problems because PHP tries to interpret the <?xml ... ?> line. In that case do something like
<?PHP
echo '<?xml ....?>';
echo 'something';
?>
This is very important if you have e.g. xhtml files.
So in order to make sure that your scripts run on all servers regardless on that setting always use <?PHP .... ?>
Thomas