[quote=Yog Sothoth]
I understand that but jk Rowling wrote the slytherins as very bad, I don't think there was any slytherin student in the books that was portrayed in a good light, hell they were not even allowed to help in the battle of Hogwarts
[/quote]

[quote]J. K. Rowling stated in a PotterCast interview that some Slytherins were among the reinforcements brought by Slughorn during the Battle of Hogwarts. [/quote]

[quote=PotterCast 131 J.K. Rowling Interview Transcript]
JN: And how much is it that being sorted into Slytherin is, you know, sorted into good guys and bad guys here?

JKR: Well, they’re not all bad, that would- I know I’ve said this before, (JN: Yeah, I remember.) and I think I said it to Emerson, they are not all bad, and, well, far from it. As we know, at the end, they may have (laughs) a slightly more highly developed sense of self-preservation then other people because…

SU: Yeah, right.

JN: Yeah.

JKR: A part of the final battle that made me smile was Slughorn galloping back with Slytherins, (SU: Yes!) (JN laughs) but they’d gone off to get reinforcements first, you know what I’m saying? But yes, they came back, they came back to fight, so I mean- but I’m sure that many people would say “Well, that’s common sense, isn’t it? Isn’t that smart, to get out, get more people and come back with them?”

JN: Yeah.

JKR: It’s the old saying, (SU: Just…) “There is no truth, (JN: I believe it.) there are only points of view.”[/quote]

([url=http://www.the-leaky-cauldron.org/2008/01/02/pottercast-131-j-k-rowling-interview-transcript/]Sauce[/url])