Stort og småt...

LOWSRC:
Using the LOWSRC attribute, it is possible to use two images in the same space. The syntax is :

<IMG SRC="hiquality.gif" LOWSRC="lowquality.gif">
Browsers that do not recognise the LOWSRC attribute cleanly ignore it and simply load the image specified by the SRC attribute.
Browsers that support this attribute however, will load the image called "lowquality.gif" on their first layout pass through the document. When the rest of the document has been completely loaded and formatted on the page, the browser will then redraw the page and load the image specified by the standard SRC attribute. This allows the author to specify a low resolution (or smaller file size version of the main image - perhaps a grey scale version) image to be displayed initially while the document is loading, which is later replaced by the higher quality version.
Any graphic file format that the browser supports can be used interchangeably within the LOWSRC and SRC attributes. You can also specify width and/or height values in the <IMG> element, and both the high-res and low-res versions of the image will be appropriately scaled to match. However, if no width and height values have been set, the values used for the LOWSRC image (i.e. the dimensions of that image) will be used to re-scale the SRC image. This is to minimise page format disruption that would be caused by the browser trying to load two different sized images into the same page space.

Brug det. Det kan også gøres vha. JavaScript, men lowsrc er et ifnt valg!

Jeg har lige prøvet <IMG SRC="hiquality.gif" LOWSRC="lowquality.gif">
I IE 6.0 der loader den bare det største billede først..
http://jens.lutzhoft.dk/billede.asp

Ja...

Så må du lige prøve dette:

<script>
stort_billede = new Image();
stort_billede.src = "hiquality.gif";
function loadDet() {
if (stort_billede.complete) document.bill.src = stort_billede.src;
else setTimeout("loadDet();",200);
}
</script>

<img src="lowquality.gif" name="bill" onLoad="loadDet();">

Tak for hjælpen