Wrap and HTML tags inside content with Shortcode

I have a shortcode for notices which works like this: [infobox]This is my information text[/infobox] The code for the infobox look like this: add_shortcode( ‘infobox’, ‘infobox’ ); function infobox($atts, $content = null) { return ‘<p class=”infobox”>’ . do_shortcode($content) . ‘</p>’; } The infobox is formatted using this: .infobox{background: none repeat scroll 0 0 #ff9; clear:both;…