[jQuery] Can I use a selector instead of this fn to check for .jpg?

[the_woodsman]

Hi all,

I have a function that determines (a bit hackily!) if an image is a
jpeg.

        isJpeg=function(src)
        {
                mySplit=src.split('.');
                extension=mySplit[mySplit.length-1];
                isJpg=(extension=='jpg' || extension=='jpeg' || 
extension=='JPG' ||
extension=='JPEG');

                return isJpg;
        };

I think I might be able to rewrite this as a JQ selector involving the
image's src attributes, something like:
$('img').filter("img[src*!='.jpg']")

But I can't get this to work- and I'm especially unsure how to do the
variations of the extension in an OR clause.

Any tips?

Thanks!