[jQuery] Problems with selectors and this keyword

[jQuery] Problems with selectors and this keyword


$('.mainTable > tbody > tr').bind("mouseover", function(){
    // alert('hi');
    //$(this + ' > td').css('background', '#ff0000'); // Didn't work
    $(this + ' td').css('background', '#ff0000'); // Doesn't either
});
I want to highlight td's in a row when I mouse over the TR's. I set
the mouseover function using the above code. The alert works when I
mouse over the row, so I then tried to select the TD children and
change their bg but it then does nothing.
Did I use this incorrectly? I'm new to jQuery and am still getting
used to the selectors.
Thanks for any advice.