jQuery returns 'none' for background-image css value

Question

I am trying to get the value of an elements background-image url. This is set in an external css file. The following always returns, 'none'.

$(".navHeader").each(function() {

                alert($(this).css("background-image"));

            });

css:

    .navHeader {
background-image:url("../../../../commondata/sharedimages/summary/NavBox_topMiddle.png");
background-repeat:no-repeat;
font-family:Arial,Helvetica,san-serif;
font-size:14px;
font-weight:normal;
line-height:16px;
text-align:center;
text-decoration:none;
}

Answer 1

Make sure that you put your code in load event which fires after even images are loaded:

$(window).load(function(){
  $(".navHeader").each(function() {
    alert($(this).css("background-image"));
  });
});

Answer 2

Try using attr instead of css.