H1-H4-H1 query

[addy]

Sorry if this is a repetition. But I couldn't get a proper answer when I searched similar questions.
Here is my question
I am on H1 right now since Nov 2008 and will be working till March 31st. After which I would like to take a break due to some personal reasons, but plan to work in future, after 6 months.
1)Incase I have to revert to H4 as COS, how long would the process take and what will be the approx charges?
2) Can I revert back to H1 in future to the same employer. My H1 is valid till 2011. In that case how much will the charges be.?

[kabkaba]

The process is called change of status.
USCIS has to receive your change of status application (H1 to H4) before you stop getting paid and when you apply for change of status the second time(H4 to H1), you need to wait until you get the approval to start working.

[addy]

say my H4 gets approved and I revert back to H1 after 2010.
1) If it is the same employer, will the charges of H4-H1 be lesser or higher?
2) I am assuming I can revert back to H1 anytime till the expiry of the same? is it correct?