i am facinated right now from the bitcoin. I am thinking get in siriusly. But there is a quation i have to do. As i understand the transactions complete when a new block is discouvered. So what will happen in the future when the blocks became more scarce?
Blocks will not become more scarce, only the reward for the block. Blocks will continue to be added to the blockchain roughly every 10 minutes or so until every bitcoin client on Earth stops 'mining' or the Sun goes supernova, whichever comes first.
2nd.. is the bitcoin client also a miner?
Yes and no. Every full
client is also capable of mining, but only if you tell it to do so. Thin and light clients don't mine, however.
and 3rd.. say i have an online store and i accept bitcoin. There is any script (php.. something) so i can understand how transactions works for the bitcoin currensy system?
There are, but I can't really direct you to such a script. They wouldn't tell you much, either, as scripts would only do a small part of the transaction handling.