hor to refer to an image within anchor?

[kusi]

i know the id of the anchor,

<a href="#" onClick="javascript:do-sth; call a js ^fn then();"><img......>

how can i refer to this image somehow, either from within anchor or from outside??

[Fang]

<a href="#" id="myimage" onClick="ChildImg(this);"><img alt="flagNL (1K)" src="images/myimage.gif" height="100" width="50" /></a>

as:
function ChildImg(obj) {
alert(obj.firstChild.src);
//or
alert(document.getElementById('myimage').firstChild.src);
}

[kusi]

Thx a lot....