simpleGallery navigation panel image

Hi All,

I am trying to use the simpleGallery and discovered that the navigation panel images are not provided.
In other words, the following declaration is at the top of the simpleGallery.js file:

var simpleGallery_navpanel={
loadinggif: 'ajaxload.gif', //full path or URL to loading gif image
panel: {height:'50px', opacity:0.5, paddingTop:'5px', fontStyle:'bold 11px Verdana'}, //customize nav panel container
images: [ 'left.gif', 'play.gif', 'right.gif', 'pause.gif'], //nav panel images (in that order)
imageSpacing: {offsetTop:[-4, 0, -4], spacing:10}, //top offset of left, play, and right images, PLUS spacing between the 3 images
slideduration: 500 //duration of slide up animation to reveal panel
}

Questions:

1- Where could I found the gif images? E.g, ajaxload.gif, left.gif, play.gif, right.gif, and pause.gif

2- And where to put these images, inside the images folder?

3- Because, I tried to put different images: at images/loading.png or images/left.png without any success.
Of course, I replaced the ajaxload.gif to images/loading.png and left.gif to images/left.png

Any suggestion will be welcomed and thanks,
Abdon.