need code for header.html and footer.html

[ilaslan]

Hello Vano and other experts

For SEO.

i need like this code ( for header html  and  footer.html )

if ( page is details page (picture page ) ) {my code }
if ( page is category page ) {my code }
if ( page is main page ) {my code }
if ( page is top picters page ) {my code }

and this code must work. but how? $cat_id is ...? ( maybe in home page . or top pages not working . but details page and cat page i need this?
if (in_array($cat_id, $cat_mypics))


Thanx all together