fullText search. Rank

hello, i'm working with full text search in sql server and i'm using the containstable to see the rank of the search, but the rank value is not correct. can you tell me what is the exact value of the rank that's appear? and sometimes when am searching for a word in full text search, the result is nothing, but in my document i have this word.. i'm searching for an arabic words and sentences.. plz help

I take it you've looked at the documentation.
If it's not working the way you expect then it could be an issue with code pages or the encoding of the text you are searching for.
Historically microsoft didn't test very well for anything that wasn't to do with US English. They have a wider beta test base now but you might have hit something that has slipped through. It could just be that the text you are typing in is different from that in the data but is displayed the same.
Try it on small amounts of test data that you know the results for.

thanks for your reply, so how can i get the frequency of the word i search for?