If you want to get the slideshow function to validate using the XHTML 1.0 Strict doctype, here's how to do it:

[list=1]
[]Copy the printSlideShowLink() function from the slideshow plugin's slideshow.php file and paste it into your theme's customfunctions.php file.
[]Give your function a new name to distinguish it from the original. I just added '2' to the end of the function name.
[]XHTML doesn't support the 'name' attribute for forms. Change "name=slideshow..." to "id=slideshow..."
[]XHTML requires form elements to be grouped using div or fieldset tags. Add div tags immediately within the form tags.
[]In order to get the form to submit using the form id, change the anchor link href to javascript:document.getElementById('slideshow_').submit()
[]Modify your album.php and image.php files to reference the new function.
[/list]
It should look like this:

`
/**

• Prints a link to call the slideshow (not shown if there are no images in the album)
• To be used on album.php and image.php
• A CSS id names 'slideshowlink' is attached to the link so it can be directly styled.
• @param string $linktext Text for the link
  */
  function printSlideShowLink2($linktext='') {
  global $_zp_current_image, $_zp_current_album, $_zp_current_search, $slideshow_instance;
  if (checkForPassword(true)) return;
  if(empty($_GET['page'])) {
  $pagenr = 1;
  } else {
  $pagenr = sanitize_numeric($_GET['page']);
  }
  $slideshowhidden = '';
  if (in_context(ZP_SEARCH)) {
  $imagenumber = '';
  $imagefile = '';
  $albumnr = 0;
  $slideshowlink = rewrite_path("/page/slideshow","index.php?p=slideshow");
  $slideshowhidden = '';
  } else {
  if(in_context(ZP_IMAGE)) {
  $imagenumber = imageNumber();
  $imagefile = $_zp_current_image->filename;
  } else {
  $imagenumber = "";
  $imagefile = "";
  }
  if (in_context(ZP_SEARCH_LINKED)) {
  $albumnr = -getAlbumID();
  $slideshowhidden = '';
  } else {
  $albumnr = getAlbumID();
  }
  $slideshowlink = rewrite_path(pathurlencode($_zp_current_album->getFolder())."/page/slideshow","index.php?p=slideshow&album=".urlencode($_zp_current_album->getFolder()));
  }
  $numberofimages = getNumImages();
  if($numberofimages != 0) {
  ?>

Thank You

Laurent