Hi we use lot of javascripts in our webpages (specially in ecomm & portal sites) for nice functionality. i just need your openion that "Is using javascript is SE friendly???" because i have read on several books (should say some reliable resources) that it should be avoided Personally i don't feel any problem using it.
Search engines cannot execute JavaScript. It is detrimental if you use if for your navigational links and it can be harmful if you load pages up with JavaScript functions. If the pages are loaded with JavaScript, it pushes the content down and can dilute its effectiveness. I sometimes see sites where almost two-thirds of the code on a page is JavaScript. Make sure that you use text hyperlinks (use CSS for rollover effects) and keep your JavaScript functions in an external file.
Depends on the way they use the javascript, some uses javascript for cloaking and creating doorway pages.
Javascripts are ignored by the SE spiders because they can only read/detect texts. Using scripts won't harm your site, it just blocks some details that might be beneficial for your site...