Today my windows were able to go down, then i went to school and tryed to make them go all the way up, and it would not fully go up. I tried and tried but eventually the window was just stuck in the middle(could not go either way). After school my freinds helped to pull the window up, while i pushed the power window button. We thought it did not work but finanly after i closed my doors to give up, on this hopeless mission, the windows came up! I want to know the cause of this and how to fix it. Also, since it is up should i risk ever opening the window again before it is fixed?