Hi Ibrahim,
as I understand this is a reproducible issue on your system and with several browsers. In our tests we are not able to reproduce this behavior and as far as we know everything should be working fine. It looks like a special issue on your computer, I'm afraid.
My recommendation to you is to try call once again this URL: http://search.sap.com/ui/scn to see if you get the correct page with the search field. If not, there are two things that you might check (if not already tried), e.g. in Firefox:
- restart Firefox with disabled addins and plugins that may cause problems (e.g. disabling of javascript, blocking of content, etc.) - but if you can reproduce the problem with all your browsers, that's probably not working (https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode#w_how-to-start-firefox-in-safe-mode)
- clear all cached web content ( https://support.mozilla.org/en-US/kb/how-clear-firefox-cache)
If all that won't help then I agree with what Jason said: maybe there is an issue with javascript on you machine. But if the SCN site with all it's features is working for you, like e.g. the forum functionality, then I would expect that javascript is ok and the search functionality should work as well.
Or did you install or configure somthing that blocks specific domains and web sites on your machine or network, so that it allow content from scn.sap.com to pass but it blocks content from search.sap.com?
Let me know if any of this helps.
Thanks and best regards,
Martin