Multiple IF criteria, return alternative value from multiple IF criteria

Hi,
I am stuck with a formula that looks simple but that is not working. Actually, I have 8 columns as follows: A2 for action items, B2 for start date, then a rage of C2, D2, E2 and F2 for the four weeks of the month; and then G2 for action closure date, and finally H2 for action status. Now, I want is this:
1) IF A2 is blank, then H2 should show "blank"
2) IF A2 contains text (action items), then H2 should show "Open"
3) IF B2 contains date (action resolution start date), then H2 should show "Ongoing"
4) IF range (C2:F2) contains "Ok", OR G2 contains date (resolution completion date), then H2 should show "closed"

The formula I tried is: =IF(A2="","",IF(ISNUMBER(B2),"Ongoing",IF(OR(COUNTIFS(C2:F2,"ok"),ISNUMBER(G2)),"Closed","Open")))
But it works only on the first 3 criteria, but would not work on the last. So, I can get Blank, Open, and Ongoing, but I can't get Closed.

Please help!