Hi on the second purple horizontal bar (on the top of the page) you will find a search tab. Depending on where you are, it will search everything in the forum, thread or post.
ie. if you press the tab on the main forum page it will seach every section thread and post. Whereas if you are at beginners discussion section it will search that section only.
Since you are in US, have a look at Ray's site
First Rays' Free Info
he is regular in this forum.