[jQuery] image replacement

[Equand]

hi all,
i'm a newbie in javascript and jquery also.
could you please help
i'm trying to write a function to do onclick of a div called img to
change img in div called 'preview'
how do i make it replace with an image which is taken from <a href="">
attribute of the img div?
$(".img").click(function(){
$(".preview img").stopAll().before('').remove();