how can i do php in jscript?

I'm not exactly sure what you want to do
PHP is a server-side language, Javascript is a client-side language. You couldn't really include PHP code in your Javascript when it's passed to the user because they would have no way to interpret it. Do you want to dynamically generate bits of Javascript?

You mean commands?

rename your .js file to .php, you probably also have to send the right header information, I think it's "header('Content-Type: text/javascript');" but don't take my word for it

<?php
header('Content-Type: text/javascript');
// do php stuff
?>
function doJavascriptStuff(x)
{
  x = '<?php echo $somePhpVariable ?>';
  // do javascript stuff
  return x;
}

Easy stuff eh?