Here's a useful script. Copy and paste it from here. I'll let the author explain what it does:

____________________________________

I wrote this simple JavaScript because I wanted information to pop up in the status bar on a onMouseOver in an image map, but I didn't want to link that specific part of the map to another document. I fixed the problem by this script:

<script language="JavaScript">
<!--
function dummyfunction(){
}
//-->
</script>

Then in the image map, I called <a href="javascript:dummyfunction()">. Then the onMouseOver was able to display info in the status bar.

If you would like to see an example of the script in action, click here.