.htaccess max_execution_time question

[RockMTP]

I need to add max_execution_time to my .htaccess file but dont know what to add. There is no code for this at the moment and my uploads seem to be timing out. The only things I have in the .ht file are:

php_value upload_max_filesize for IfModule mod_php5.c & mod_php4.c

php_value post_max_size for IfModule ... If that all makes sense!?

Can someone please tell me the code I would need to enter?

Thanks