Idle+Walk animation problem and double-button input axes

Question

I have 2 problems with unity3d.

First, I created an animator and attached it to player. In animator I put 2 condition, Speed and Running (first is float, second is boolean). Default Animation is Idle. Then player press W, I want animation to fade from idle to walk and when he stop press the button, I want the animation to fade from walk to idle. Here is my problem.

1. When I press W, he make walk animation, but after it he play half of idle animation and after it he enter again in walk animation. How can I loop the walk animation until he release W? And if he release, even if the animation isn't totally played, I need the animator to make transition to idle.
2. How can I make this "transition"? Then I release W, he just go from walk to idle animation without any transition (and it is a kind of wear).

Second, How can I put 2 input buttons on axes? I mean: If he press W, there should go vertical axes. When he press W+Left Shift, there should go running axes. How can I attach 2 buttons to 1 axes?

I am new in unity and I want to figure out how to work with this things.

Answer 1

Just set your walk animation in the Unity inspector to loop, and use animation.CrossFade for the transition.

if (...) {
  animation.CrossFade (Run.name);                               
} else {
  animation.CrossFade (Idle.name);
}

You can use this for idle animations as well:

if (!animation.isPlaying)
  animation.Play(Idle.name);