Animation on Mouse Button

Hi,

I'm working on a project just as a hobby here, learning as I go along.. I'm having trouble figuring out the best way to control animations (during movement). When I hold both mouse buttons down, I'm able to move but the "run" animation starts and freezes in the first frame. From what I understand here, anim.Play() is resetting over and over, instead of playing out but I can't figure out how to do this another way.

Code (CSharp):

1.     void Update(){
2.        
3.         anim = GetComponent<Animator>();
4.         anim.Play("idle", 0, 0f);
5.         if(Input.GetMouseButton(0) && Input.GetMouseButton(1)){
6.             SetTargetPosition();
7.             Move();
8.             anim.Play("run", 0, 0f);
9.         }
10.     }