If you want to have the text tabbed when pressing tab in textareas rather than it switching fields.

$(document).delegate('textarea', 'keydown', function(e) { 
  var keyCode = e.keyCode || e.which; 

  if (keyCode == 9) { 
    e.preventDefault(); 
    var start = $(this).get(0).selectionStart;
    var end = $(this).get(0).selectionEnd;

    $(this).val($(this).val().substring(0, start)
                + "\t"
                + $(this).val().substring(end));

    $(this).get(0).selectionStart = 
    $(this).get(0).selectionEnd = start + 1;
  } 
});