can you tell me how to fix this error i am getting on my php script. i checked my code

Parse error: parse error, unexpected T_CONSTANT_ENCAPSED_STRING in /var/www/webs/mydomain/inc/functions.php on line 474


UPDATE: never mind, i figure it out.

this is how i had my code in line 474:

PHP CODE:
return 'cat='.$id'&pg='.$page_num ;


so i changed it to

PHP CODE:
return 'cat='.$id.'&pg='.$page_num ;


can you see the difference?