To Strike out, or cross out a word or phrase....
1) write your message, equation or whatever you wish to "strike thru"
2) click in the "Use HTML to create your page" box at the bottom of your posting box (or page you are creating).
3) find the word, sentence or whatever you have chosen, and place a: <S> right infront of it, and a </S> at the end of it.
4) click back in the "Use HTML..." box so the check mark disappears, and you shall see your words with a strike through them.
here's what i mean:
please strike through only the three words in the middle of this sentence.