help! Serbian difficulties

I have just started studying Serbian and unfortunately my book has a few holes in it so I'm not quite following what is going on. I hope there is a Serbian speaker out there. Can someone please check what I have done below, especially the ones with questions marks next to them, or can anyone provide me with some rules (thanks in advance):

1. One juice (nom, masc.) - Jedan sok

2. One water (nom, fem.) - Jedna voda

3. One beer (nom, neu.) - Jedno pivo

4. Two juices (pl., nom., masc.) - Dva soka

5. Two waters (pl., nom, fem) - Dve vode

6. Two beers (pl., nom., neu.)- Dva piva

7. I want one juice (acc, masc) - Hocu jedan sok

8. I want one water (acc, fem) - Hocu jednu vodu

9. I want one beer (acc, neu) - Hocu jedno pivo

10. I want two juices (pl, acc, masc) - Hocu dva soka

11. I want two waters (pl, acc, fem) - Hocu dve vode

12. I want two beers (pl, acc, neu) - Hocu dva piva

13. A glass of juice (gen., masc.) - Casa soka

14. A glass of water (gen., fem.) - Casa vode

15. A glass of beer (gen., neu.) - Casa piva

16. I want one glass of juice (acc., masc.) - Hocu jedan casa soka (?)

17. I want one glass of water (acc., fem.) - Hocu jednu casu vodu (?)

18. I want one glass of beer (acc., neu.) - Hocu jedno casa piva (?)

19. I want two glasses of juice (pl., acc., masc.) - Hocu dva casa soka (?)

20. I want two glasses of water (pl., acc., fem.) - Hocu dve case vode (?)

21. I want two glasses of beer (pl., acc., neu.) - Hocu dva casa piva (?)

I forgot to add:

A. Two glasses of juice (pl, gen., masc.) - Dva case soka ?

B. Two glasses of water (pl, gen., fem.) - Dve case vode?

C. Two glasses of beer (pl, gen., neu.) - Dva case piva?

I really dont have any ideas as to these ones...

I was thinking (16) might be "Hocu jedna casa soka", (17) "Hocu jednu casu vode" and (18) "Hocu jedna casa piva"

Thanks for any help

Hocu [jednu] casu soka.
Hocu [jednu] casu vode.
Hocu [jednu] casu piva.

Kako si bre?

Ja cam dobro, ucim ucim!

Hvala za tvoj pomoc!
Ali za brojovi 16-21? Sta mislis?
Nadam ja mozam da pisem tacno!

i za A-C?

16 - sesnaest (can't use that little sign above the first "s")
17 - sedamnaest
18 - osamnaest
19 - devetnaest
20 - dvadeset
21 - dvadeset jedan

No, Sanja. I think she meant examples 16 through 21 in her first post.

16. Hocu (jednu) casu soka
17. Hocu (jednu) casu vode
18. Hocu (jednu) casu piva
Instead of "hocu", you can use "molim" ("please") when asking, that's more polite.
19-21. dve case (u svim slucajevima/in all cases)
A-C. dve case (in all cases)

Oops, sorry. I thought she wanted to know how to write numbers 16 - 21. LOL :))

When ordering something, I'd say:

Molim Vas (jednu) čašu soka/vode etc.

Or

Čašu vode/soka, molim Vas.

For beer, it is customary simply to say

Jedno pivo, molim Vas.

(But, of course, dva piva, tri piva, osam piva etc.)

č = ch

:-(