Checking for and loading the correct image

[Anon]

Hi,

I think this involves a lot more JavaScript help than PHP, but I can't seem to find a decent JavaScript forum and I know a lot of you are javascript guru's.

Basically, I'm allowing people to upload graphics to my web site. When they upload graphics, a table in the mySQL database is updated to include information about the picture. The picture is also given a number (the number is auto-incremented). The picture can also either be gif or jpg.

So, for example, after 6 people have uploaded pictures, here's what I might have saved on my server:

0.gif
1.gif
2.jpg
3.gif
4.jpg
5.jpg
6.jpg

Good so far? Now here's the trick.. On one of my pages, you can review the graphics that are on the server. Each picture is shown one at a time, with graphical arrows to each side

<< | picture | >>

like that, sort of. Now, without reloading any part of the page each time, I need to change that picture to the next one in the series. JavaScript, would be, of course, the obvious choice here because it doesn't have to refresh the page. But, the JavaScript is going to have to know whether the picture is 0.gif or 0.jpg without referring to the database, so it can show the one that's correct. Is there a way, with JavaScript, that I can test to see if an image (like 0.gif) exists, and if it doesn't, use the other extension?

Thanks a lot,
Joseph

[Anon]

My suggestion, and this isn't the code for it, would be to have all the images layed on top of one another in layers. On click of "next", it shows the next proceeding layer. You could probably use a for loop to do that, and just start at the obvious id "0" in the database, and use php variables for the rest of it....make sense?

If it doesn't, I spose I could code it for ya, but I always know figuring it out for myself is oh soooo satisfying ;-).

[Anon]

trying loading all of the images in the directory into an array....

then use php to print out the javascript code, with the array of images..

then you could use javascript to loop through that array, since it's already defined, you don't have to query the db...

Brooks