Really like the game so far. Right off the bat, the visuals are really good, and you can tell you're putting your time into the rendering to make it look good. I applaud you.
Josefus is talking about julia1_4.html where Pictures/julia_talk2.png doesn't exist yet. Probably just wasn't in the folder. Other than that, the game design is good. Very unforgiving, which is something I suggest you keep, because it really does increase the replay value of the game. I like the way the characters are taking shape, you seem to have a clear idea of who you want your characters, and the execution works.
My only criticism is that so far, there's a lack of dialogue. Obviously, I don't know what your final vision is, but, for example, the walk down the hallway with Fiona could be more involved. The one Headmaster/Mistress page was very text heavy, you could break that up over multiple clicks. Use it to really explain the role of the janitor with cleaning, etc. However, take that with a grain of salt, because they are your characters and characterizations, and dialogue for the sake of dialogue can ruin that.
Very well done so far. Really looking forward to the complete game!