Java script syntax doubt

Question

Hi all,
I am creating a folder tree using xml,xsl,javascript...
In that - I am passing the div tag object to a function as an argument named for intstance as diventity
in javascript what does the following code does...
function expand(diventity) {
var oImage
oImage = entity.childNodes(0).all["image"]--- What does this code does .
oImage.src = entity.imageOpen
}