Violin players i need your help!?

What are some ways to keep me from moving my bow from moving towards the left i need to keep on right in the middle....plz i need tips

play in front of a mirror, and observe closely what your arm, wrist, and elbow do that make the bow move toward the fingerboard.
There should be a fluid movement transitioning from upper bow to lower bow.

Look at the position of your bow arm and wrist. You may need to change the angles as you play. Practice makes perfect.

u mean to the fingerboard? well look at ur bow while bowing and if it gets closer to the fingerboard just change the angle of ur wrist continusly. it might feel wierd at first but if u keep doing it it'll become perfect!

See:

(17) What is the best method to produce a straight bow?
http://beststudentviolins.com/PedagogyTe...

I recommend Simon Fischer's _Basics_ which is rather expensive, but it full of great bowing exercises. See link.