when you post on forums, how do you increase the space between each line with out pushing enter lots of times? :) please help

I think that's the only way...

You don't. At least, not on these forums. Line-height isn't a major concern for most forum-goers. However, if a forum were to support HTML in posts (we don't), you might get away with something like this:

<p style="line-height:2em;">The line height of this paragraph is twice the height of it's font-size.</p>