key problems&animation

hey guys how are you i am fine. i have a problem with my animation on thats on my gun when i press fire 1 my gun fires and does its animation thats all good But!!!!! when i do this and i want to walk so i than i want to hold fire 1 and press W together than the problem appears. my gun animation doesnt play annymore. how can i fix this?? maybe his will help here is my script

(terugslag) is dutch for (recoil).

function Update() 
{

if( Input.GetButton( "Fire1" ) )
{
animation.Play("p90 terugslag");
}
if( Input.GetButtonUp( "Fire1" ) )
{
 animation.Stop("p90 terugslag");
}
}

You need to use “Blend”.

http://unity3d.com/support/documentation/ScriptReference/Animation.Blend.html

Instead of calling play, when ever you want to activate an animation which needs to work along other animation clips do a call to blend:

animation.Blend("p90 terugslag", 1, 0.3);

animation.Blend("walk", 1, 0.3);

etc…