Every web page within an overall web site should include a standardized list of Hypertext links connecting individual pages to the rest of the web site and vise versa. This list of hypertext know as the navigation menu needs to appear on every page of the web site... For the purpose of this example: I am guilty of breaking my own rule ...Notice that hosting horse's main navigation is not on this page (This drop down example contains only code that is absolutely essayer to achieve desired functionality and face.
Listing Hypertext leading to main categories (the three main menu chooses could be screen as the only blemish in the HTML, I would have to agree that I would like those main menu options to look just as clean in the code as the rest of the links on the menu, however I am un-cert in as to any way (or even a good reason now that I think about it) to worried about this kind of JavaScript link not being followed by the spiders; the JavaScript links that are a major red flag are the kind that activate the changing of the page with a .JS function. So, to sum up, you may want to check your own drop down menu to be sure it allows the spiders to crawl through the pages on your site as your visitors can. So view your source and look for the following tell tail signs of a "Search Engine Spider Stopper Style Drop Down Menu"
Here are what you should check for: Are there actual href tags leading to the pages accessed using the drop down navigation on your web pages?Search engine spiders are extremely unlikely to be able to identify (much less crawl and catalog) URL's being used to perform functions within the script. & switching from function actuated navigation to HTML centric menu structure is a virtual Nesting ground for search engine spiders