JQuery :: Detect Size Of An Image?

This is an update to a previous question which didn't get any replies. Having tried some things it boils down to a question of whether jQuery can detect the width of an image on the page when that width hasn't been defined in the image tag or css.

I'm designing templates for other authors to use. If they put an image of over a certain width in a div it'll break the layout. I've tried to write a function that gets (1) the name of the div and (2) the maximum width allowable. It should then check the images in that div and if they're over the maximum width, resize them to the maximum width. If they're under it should leave them alone. If a width is defined in the the width attribute it should leave it alone.

I know that is what 'max-width' is for, but the browser in our organization is IE6 and that's not going to change anytime soon. It ignores 'max-width'.

[Code]..

The result each time I tinker with it is that either it does nothing or it sets the widths of all images to maxwide, even the small ones. I'm doing wrong? The only clue I have is that if I alert the width of images going through the function, those without a defined width come up as 'auto', which it seems to think is greater than maxwide.