Design-Once Feature Compatibility
When designing InfoPath form templates for use in both Microsoft Office InfoPath 2007 and in a Web browser, there is a small set of features that are hidden from the InfoPath design user interface (UI). These features are available if a form template is created for use in the InfoPath client, but they are exceptions to the Design-Once development principle of Office InfoPath 2007. Design-Once refers to the ability to design a form template that is capable of being used in InfoPath and rendered in a Web browser by a server running InfoPath Forms Services.
Exceptions include some controls, such as the Master/Detail control and the Vertical Label control, some features, such as user roles and spell checking, and code written in the scripting languages JScript and VBScript and the backward-compatible managed code languages introduced with Office InfoPath 2003 with Service Pack 1. For more information, see Creating InfoPath Form Templates That Work With Forms Services in the Microsoft Visual Studio Tools for Applications (VSTA) or Microsoft Visual Studio 2005 Tools for the 2007 Microsoft Office System Help system.
If you are designing a form to be used in both InfoPath and in a Web browser, and you need to use excluded object model members when the form is opened in InfoPath, you can hide errors in the Design Checker task pane. To do this, click the Tools menu, then Form Options in the InfoPath design UI to open the Form Options dialog box. On the Compatibility category in the Form Options dialog box, click the Hide errors for code that uses InfoPath-only features check box. To determine the environment in which the form is currently open, use the Environment property of the Application class. More information about using this property can be found in the Microsoft Visual Studio Tools for Applications (VSTA) or Microsoft Visual Studio 2005 Tools for the 2007 Microsoft Office System Help system.