rem: Element.remove(row); 
add: if (null != row) { Element.remove(row); } 
context: function SessionList() {    var deleteUrl = 'delete-session.xqy';    var renameUrl = 'rename-session.xqy';    this.newSession = function() {        // start a new session and set the user cookie appropriately        debug.print("newSession: start");        // setting the session uri to gSessionDirectory signals        // lib-controller.xqy to build a new session.        setCookie(gSessionUriCookie, gSessionDirectory);        // refresh should show the query view        window.location.replace( "." );    }    this.resumeSession = function(sessionUri) {        debug.print("resumeSession: start");        // set cookie to the new uri        setCookie(gSessionUriCookie, sessionUri);        // refresh should show the query view        window.location.replace( "." );    }    this.deleteSession = function(uri, context) {        // delete the session        debug.print("deleteSession: " + uri);        if (confirm("Are you sure you want to delete this session?")) {            // call session-delete            var req = new Ajax.Request(deleteUrl,                {                    method: 'post',                    parameters: 'URI=' + uri,                    asynchronous: false,                    onFailure: reportError                });            // delete the item from the DOM            // context will be the button            var row = context.parentNode.parentNode;            Element.remove(row);        }    }    this.renameSession = function(uri, name) {        debug.print("renameSession: " + uri + " to " + name);        // call the rename xqy        var req = new Ajax.Request(renameUrl,            {                method: 'post',                parameters: 'URI=' + uri + '&NAME=' + name,                asynchronous: false,                onFailure: reportError            });    }} // SessionListClass
meta: 952	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/952/69dedb9c0ffc0c9e18f6293f86204bb722b72414/session.js/buggy/session.js