shortcodes displaying outside of content area with echo statement, not what I wanted [duplicate]

Shortcode functions are supposed to “return” the value, not echo it:
http://codex.wordpress.org/Shortcode_API

//[carouselle]
function carouselle_func( $atts ){
 return "<h1>Some HTML Stuff</h1>";
}
add_shortcode( 'carouselle', 'carouselle_func' );