newbie, question

[Guest]

how do you insert a small portion of what the other person said or ask then reply to that question? you know, the grey box and says something to the effect, mrs x said, then you answer that portion.
thanks
also, many times when i reply and submit, message comes up. invalid session, pls try again.

 

[roki]

you press the quote button on the upper right side of the post

 

[Guest]

thanks, but when ya press the quote button, how do you only obtain a certain part of someone's reply?