find word of 'John' in div.content using :contains() selector and add CSS style property
$('.content:contains('John')' ).css( "text-decoration", "underline" );
remove the word page from id
$('#forum-cat:contains(page)').filter(function() { return $(this).children().length === 0; // exclude divs with children }).text(function(index, text) { return text.replace(/page/g, ''); });