rem: if (filterSelected) { reorderUpButton.disabled = !filters[0].previousSibling; reorderDownButton.disabled = !filters[0].nextSibling; } else { reorderUpButton.disabled = true; reorderDownButton.disabled = true; } 
add: reorderUpButton.disabled = !(filterSelected && gFilterTree.currentIndex > 0); reorderDownButton.disabled = !(filterSelected && gFilterTree.currentIndex < gFilterTree.view.rowCount-1); 
context: function updateButtons(){    var filters = document.getElementById("filterTree").selectedItems;    var filterSelected = (filters.length > 0)    editButton.disabled = !filterSelected;    deleteButton.disabled = !filterSelected;    if (filterSelected) {        reorderUpButton.disabled = !filters[0].previousSibling;        reorderDownButton.disabled = !filters[0].nextSibling;    } else {        reorderUpButton.disabled = true;        reorderDownButton.disabled = true;    }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/07d96867f11683becf5e1a6ca5e64e6a9324c957/FilterListDialog.js/buggy/mailnews/base/search/resources/content/FilterListDialog.js