Guys suppose our main page is just an intro page not flash based but a normal intro based linking to all our services .. would this damage the sites search engine positioning.. the content will be less
It is depends on how internal linking you would done. If they are common links to internal pages without an "overdoing" then it would be fine. Otherwise your website ranking would be a little dropped due to change in internal linking anyway - for a temporarily period.
Just be sure to have a good, descriptiive meta description, title, and tags, and h1 header. You don't necessarily need "a lot" of content, but enough to help the SE's figure out what the page is about.
If you are using on normal links building for your internal pages, its OK and you have done it in a search engine friendly manner.
If your meta tags and keywords are good of the first page then it should not make nay problems as well as make sure that the internal linking is done properly as well as make a sitemap so you can allow Google to crawl all of your pages. And also it will be good if you use quality content on your intro page.