Changing Default Animation?

I made a walking Animation. Found here: http://www.roblox.com/walk-item?id=294924898 When I change the default walking animation to this, (using this script:)

Game.Players.PlayerAdded:connect(function(player)
    while not player.Character do wait() end
    local character = player.Character
    local animateScript = character.Animate
    animateScript.walk.WalkAnim.AnimationId = 'http://www.roblox.com/asset/?id=294924898'
end)

This is my output: (PS, HTTP Service is on.)

12:59:48.646 - httpGet http://www.roblox.com/asset/?id=294924898&serverplaceid=95206881&clientinsert=0 failed. Trying again. Error: HTTP 403 (HTTP/1.1 403 Asset is not trusted for this place).  Elapsed time: 0.0837234
12:59:48.735 - Content failed for http://www.roblox.com/Asset/?id=294924898&serverplaceid=95206881&clientinsert=0 because HTTP 403 (HTTP/1.1 403 Asset is not trusted for this place)
12:59:48.736 - Content failed because HTTP 403 (HTTP/1.1 403 Asset is not trusted for this place)