Why does it fail to load the background picture of the left categry?

Link:https://www.rustydiary.com
I try to change the background of the left categry, but always fail. urgent! Thanks very much.

What did you change it to??

Image name and path to the image

The original background of the category is white (color) and I wanna replace it with the background-image, but it fail. If you use firebug CSS, you can see the image url fail in the id=navColumnOne element.

#navColumnOne {
    background: url("../images/cat-bk.pgn") no-repeat scroll 0 0 transparent;
}
``` What kind of image is ".pgn"? :)

Also, do you really want the "cat-bk" image on the entire left column? There is already an image that takes care of that, except for where the categories are. You may want that background on the #categories element; or you may not need a new image at all, depending on the result you want. Do you want some special categories image, or just to match the rest of the page? If you want to match, you need to eliminate the background colors by making rules for the #categoriesHeading and #categoriesContent sub-elements.

I believe you will need to do this as well as moving cat-bk.png to the #categories element, or it may be ok to leave the categories background assigned to the left column. You won't be able to accommodate changes to the size of the menu with the bg image you have now..