animating my enemies

hey guys, iv imported my enemy model from 3ds max and i have 3 animations names in unity, idle, walk and die. an new to unity btw.

i have the enemy following me but he just slides towards me. i'v added this code but it's not playing his animation. i simply just want to loop the animation 'walk' since it is the same as idle. ill get round to adding his death animation when i have added script for killing him.

function start ()
{
    animation.Play ("idle");
}

all help appreciated

One thing I notice is that start() is in lowercase - it should be Start(). If that isn't the problem, then you need to post more details.