Cache object, application data and caching application data latency and pages browser type and custom strings and query string parameters and version and scalability and user controls Catch block, page-level tracing and categories, trace log charts [See bar charts ] checkboxes, arrays displayed as CheckBoxList control checkForReturn function, keypress event and classes code-behind, reusing custom configuration handlers delegate classes Hashtable HTTP-specific information access TraceContext VBSiteConfigHandler VBSiteConfiguration client validation CLR (Common Language Runtime) tracing and web services and code-behind classes, reusing columnar data, DataGrid control components , dual-use concatenation, StringBuilder object and conditional breakpoints, debugging and configuration [See also web.config] file hierarchy state, maintaining across servers <configuration> element, web.config configuration handlers, custom ConfigurationSettings.GetConfig, custom configuration confirmation pop up, row deletion, DataGrid consuming web services Control class custom controls and WebControl class comparison controls CheckBoxList custom attributes HTML controls and state and CustomValidator DataGrid DataList focus validation errors RangeValidator RegularExpressionValidator Repeater RequiredFieldValidator 2nd tabular, selecting TextBox, numeric input 2nd user controls caching communication between destination controls dynamically adding source controls validation [See validators] xmlTransform cookieless atttribute CultureInfo object, currency format and currency, formatting override custom controls attributes and HTML controls and combining properties state and custom objects, web services and CustomValidator control, drop-down lists