nifty futures

hi all , i ve been trading for a while now in nifty options , i want to know about futures , i browsed around and found some details but i have a few doubts ,

is nifty future only intraday ? will i be able to hold overnight ?
does its price reduce with time like options ?
will i be able to close my trade only up on expiration ? if not why do they have expiration period ?
what kind of tax prices i can expect for one lot of nifty traded.

Please help . THanks

Hi,
Nifty futures can be carry forwarded to next day ....
No, its not affected by time ....
No, position can be initiated & closed any number of times until expiry...Futures are contracts between two parties and part of its pricing depends upon cost of carry(intrest costs)...so there should be a time frame(Expiry) ...that's why expiry..
I could not understand your last question....
Please go through the following link for information and better understanding about Futures contracts.....
http://www.nseindia.com/education/content/module_ncfm.htm
Please download study material in pdf format from the above link....
Equity derivatives: A beginners module....
All the Best
Praveen

Thanks a lot !!