Character dialogue???

Okay, i know there's some advise-topic somewhere in this huge, huge forum, but i just wanna post this so that i would get the answer straight and so that i can ask you guys.

Er... i'm writing a new story, about devils and angels, which doesn't even matter, but i just kinda wondering on how you guys write the dialougue for the chars???

For example :"Oh hai". "Hi there," a voice said behind me. I turned back. A young man was standing behind me, naked. His cock erected. Gayness filled the room with horrible scents. "What.... the... hell!!!!" I screamed. The man walked closer and closer, his footsteps echoing through the narrow stone corridoor. I can't seem to move my legs. All went black.
My virginity was taken from me by a guy.
lol. XD

ANYWAYS, thanks for answering my questions in advance and any questions to me, ask through the comments! Again, thanks!!! :P

I'm not an expert in writing but, I'm assuming that the person who said "Oh Hai" and "Hi there" are two different people, I'm sure that when writing, when another person says his dialogue, it starts on a new line.

Example: "Oh hai."

"Hi there," a voice said behind me. I turned back. A young man was standing behind me, naked. His cock erected. Gayness filled the room with horrible scents. "What.... the... hell!!!!" I screamed. The man walked closer and closer, his footsteps echoing through the narrow stone corridoor. I can't seem to move my legs. All went black.
My virginity was taken from me by a guy.

Also, when writing dialogue, the punctuation marks (e.g. fullstops, commas, question marks, etc) are inside the quotation marks. I saw that when you wrote "Oh Hai" you put the fullstop outside the quotation mark.

I'm not a grammar nazi btw. . .

Oh, thanks. That was just an example. I just wanna know how others would write/describe a scene like this. XD

"Oh hai," I said. (Can't tell if that's you speaking, so I'm assuming)

"Hi there," a voice said behind me. I turned back. A young man was standing behind me, naked. His cock erect. A feeling of homosexuality filled the room with its horrible scents.

"What...the...hell!!!!" I screamed. The man walked closer and closer, his footsteps echoing through the narrow stone corridor. I couldn't seem to move my legs. All went black.

My virginity was taken from me by a guy.

BTW: I am a grammar hermit. I believe in proper English, but I keep it to myself unless asked. You asked. I also fixed a lot of random things like 'erected' into 'erect' and 'gayness' into 'a feeling of homosexuality.'

Have a good day.

Thanks! I owe you one. XD