[youtube]S1Tpt_RNl8g[/youtube]
If this is what you mean, the code works like this:
just like an image code, you have a word contained in [] brackets. in this case it's [youtube ][/youtube ], except without the space at the end. When you look at any youtube link, you'll see an = sign and then a set of numbers and letters at the end of the url. the stuff after the = sign is what you'll use to put in between the youtube bracket code. in this case:
http://youtube.com/watch?v=S1Tpt_RNl8g
so for this video it's [youtube ]S1Tpt_RNl8g[/youtube ], except without the spaces at the end of "youtube".
Thats for bladeforums specifically though. normally on most websites, you can insert the link found in the "embed" box on the youtube page. for this video, the embed code would be
<object width="425" height="355"><param name="movie" value="http://www.youtube.com/v/S1Tpt_RNl8g&hl=en"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/S1Tpt_RNl8g&hl=en" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355"></embed></object>
But bladeforums doesn't recognize html code.