the_content and post_type problem

Trying to add something here. But NOT when the post type is static_block

I really cant figure out how to show something when the post is NOT static_block,

The theme i am using is inputting the_content other places and i dont want the image i am trying to add. like 5 places.

Anyone?

<?php
 function reklame_under($content) {
 	if (is_singular() && $post->post_type != "static_block" ){
			   $reklame = '
				<div style="width:468px; margin:5px auto;">
                                 Trying to add something here. But NOT when the post type is static_block
				</div>
				<br/>
			';
			   return $content.$reklame;
 	}

 	else {
 		return $content;
 		}
 }
 add_filter('the_content', 'reklame_under', '100');
?>