To stop you from having writers block, the best thing is to always carry around a notebook, if you get ideas jot them down straight away so you don't forget them later. Also, don't just write your chapters out in a sequence one after the other, if you want something to happen sometime in your story write it down, you can always work the chapters order out later ^___^
Also an idea is if you are writing a chapter, leave it unfinished, you can write the plot out, but then you will have something to write when you come back later.

thank you.that is good advice=)

I've dealt with this problem recently (really recently, like...today), and (purely by coincedence, really) I read some fanfiction LIKE the one I'm writing, and poof, I'm back writing. It works.

Yep, like "LilysLittleTwin" said, read lots and lots of fanfics. I'm not saying copy their ideas, but sometimes, while reading someone's works, a idea pops into your mind. I'm a strictly one-shot and drabble writer, so the Harry Potter Fanfiction Challenges Forum in my cure to writer's block. There's idea rampaging all over the place over there. xD

I´m up for the carrying a notebook for writting ideas on! I also think you shouldn´t post a foc until you know really well where are you goin

These are all good points, but they barely halp with my problems. Because it's not ideas that I have a problem with; I tend to get stuck on dialogue.

^then...get help from a beta-reader?

Music. Listen to a song that reminds you of your story. That's my biggest help.

Second for me is if I watch a new episode of whatever I'm writing about and BAM I'm back

Or reading fanfic, but sometimes you just have to wait for it to pass

Some good tips here. I would add possibly either writing out the complete story before publishing, or at least have a general outline subject to change. Definitely bring a pencil and paper around with you.