You need to use colon :
instead of semi-colon ;
here after your if
condition:
if($advs->is_checked == "1"):
// ----------------------- ^ here
if($advs->is_checked == "2"):
// ----------------------- ^ and here
From the docs:
PHP offers an alternative syntax for some of its control structures; namely, if, while, for, foreach, and switch. In each case, the basic form of the alternate syntax is to change the opening brace to a colon (:) and the closing brace to endif;, endwhile;, endfor;, endforeach;, or endswitch;, respectively.