Hello 'rushdi09',
Retracting a bid is considered very poor form. Hence, there are only a few circumstances in which it is permitted. Have a look at the following link to tell you more about it:
http://pages.ebay.ca/help/buy/questions/retract-bid.html
You can also ask the seller to retract your bid for you, but you can be sure whilst she's doing you the favour she'll add you to her list of blocked bidders.
In future, when you see an item you think you want to bid on, instead of bidding right away, use the Add to Watch list option which is right below. It puts the listing in your Watch List that you can access from the left side of the page, or the My eBay at the top. All the items you are contemplating can be stored this way, and it gives you time to be sure.
Sellers don't like retractors. Better to be a watcher until you are ready to be a buyer, - and a prompt paying buyer at that. 😉
