Find the position in a list

Find the position in a list

I can't find the key word or way to get the position in the set of list items.  Here is the example code:
$('.mainMenu a').click(function(){
     var $target = $(this).attr('id');
     /* var $number = $(this).offset(); */
     $("#response").text("Menu choice '" + $target + "' was chosen, OK! "
     + "it was the '" + $number + "' item on the list");
});
Also how do you generate a line break or CR
Thanks!