[jQuery] Get first child within an element

[dgb]

Hi,

I've got a reference to a TableCell and I'd like to use jQuery to get
the first instance of an <IMG> tag within that TableCell, but can't
get the syntax right, I understand how it would work if I were to
reference the TableCell by and ID or class, but not when I have a
direct reference to the cell, I've got:

var tdRef = xxx;

$(tdRef).html();

... could somebody let me know what the jQuery syntax should be to get
the first img tag within "tdRef"?

Thanks! :-)