Today, we're beginning a troubleshooting series to help you diagnose and solve common issues with your ads, search boxes, and account functionality. We're kicking things off with a look at how to correctly implement your ad code and an explanation of why ads may not appear on your pages at times.

First, the best way to ensure ads are served correctly is to copy and paste the code exactly as it's provided in your account. Changing the code and manipulating ad behavior aren't permitted by our program policies, and in most cases will prevent your ad from appearing at all.

If you've noticed that your ad units aren't showing ads, here are a few things to check for:

• Did you just add the code to that page? Relevant ads should appear on your pages shortly after you add the code, but sometimes it can take up to 48 hours for ads to show. This is because our crawler has to visit your page and determine its content so we can serve targeted ads.
  
  
• Does the code on your page match the code in your account? Make sure to copy the code exactly as it appears in your account, and paste it within the body tags of your HTML code. Be sure not to make any changes to the linebreaks of the code (e.g. pasting the code all in one line) as this will break the code and prevent ads from showing entirely.
  
  
• Are you using an HTML editor? Publishers often use a design-enhanced HTML editor like Macromedia Dreamweaver or Microsoft FrontPage (aka WYSIWIG, "what you see is what you get" software). If you use such an editor, you may see errors if you paste your ad code into a WYSIWYG view such as the "Design" or "Layout" view. For the ads to function properly, you'll have to copy and paste the ad code into the HTML source code of your webpage using the editor's HTML view or HTML insert function. Check for any additional tags inserted by the system or changes in the linebreaks.
  
  
• Are you using a content management system (CMS)? If you have trouble implementing AdSense with a specific content management system, we recommend searching for the name of the CMS (eg. Drupal, WordPress) and 'AdSense implementation'. You can also ask in the forum if other publishers have mastered similar problems, or contact your program provider directly.
  
  
• Are the ads inside nested frames? While you can choose where to position your ads on your pages, be sure to avoid embedding the ad code in excessive div tags or nested frames. Depending on your browser settings, implementing your ad code in this way might prevent ads from appearing correctly.
  
  
• Is JavaScript enabled in your browser? Ensure that you have JavaScript enabled in your browser, as this is necessary to view ads! If you're having trouble seeing the ads, please also check for any conflicting JavaScript on your site that might prevent ads from showing.
  
  
• Is your page dynamically generated? If you'd like to implement AdSense ads on a dynamically generated site -- for example, a site with session IDs or pages behind a login -- you should take a look at this Help Center entry for more information on how to receive targeted ads.

In the next part of this series, we'll provide tips to help you troubleshoot ad relevancy and targeting issues.

Posted by Ulrike Jung - Inside AdSense Team