Attribute for <IMG ...>
onLoad = "script command(s)"

The onLoad event is fired when the image is finished being downloaded. For example, the following code displays an alert box when the image is downloaded:

<IMG 
  SRC="../graphics/pumpkin.gif" ALT="picture of a pumpkin"
  HEIGHT=100 WIDTH=100 
  onLoad="alert('loaded')">

which gives us

Unfortunately, onLoad is not a very reliable event handler. Netscape particularly has trouble firing onLoad when the image is malformed in some way or if the image is loaded from cache instead of freshly downloaded from the net.