If you create a link with a target="_blank" attribute, the corresponding value shows as selected. When the Link Manager is opened second time the value shows as selected, but the link is not set without a target attribute. You can find attached a sample project, in which is used the Custom Built-In dialogs approach to resolve the problem. For details about this approach follow this link: http://demos.telerik.com/aspnet-ajax/editor/examples/externaldialogspath/defaultcs.aspx