Apostrophes don't work in browsers

In several locations, apostrophes are used to contain styles, URLs, etc. These did not process properly in my environment so I had to replace them all with escaped quotes like those (below) around fl-link, fl-image, and the href URLs:

function theme_facebook_link_item($link) {
  $output = "<div class=\"fl-link\">";
  if (isset($link->image) && !empty($link->image) && ($link->image != '')) {
    $output .= "<div class=\"fl-image\">";
    $output .= "<a href=\"". check_url($link->url) ."\">";
    $attributes = array('width' => variable_get('facebook_link_image_width', 100),
    );
    $output .= theme_image($link->image, $link->title, $link->title, $attributes, FALSE);
    $output .= "</a></div>";
  }

  $output .= "<div class=\"fl-title\">" . "<a href=\"". check_url($link->url) ."\">". check_plain($link->title) ."</a></div>";

  if (isset($link->description) && !empty($link->description) && ($link->description != '')) {
    $output .= "<div class=\"fl-description\">". check_plain($link->description) ."</div>";
  }

As I'm not a skilled coder so I don't know if this is the right way to fix it... but it resolved my issue.