Property Overrides Dialog Box
Use the Property Overrides dialog box to override existing property values for a specific target device.
You must apply device filters to the control using the Applied Device Filters dialog box before you can override properties for a given device. Overridden property values are not rendered in Design view. You will need to view them on an appropriate emulator or target device.
To access this dialog box
In Visual Studio, open or create a mobile Web page.
Switch to Design view.
In the Properties window, in the (PropertyOverrides) box, click the ellipsis button ().
If you delete the value of an overridden property and do not specify another value, the property will contain an empty string. To remove the overridden value so that the property will no longer be overridden, you must enter the exact value of that property.
For example, suppose that the default text for a Label control's Text property is the string "Please enter a text string:" and the overridden value for a particular device filter is "Enter a string:". To remove the overridden value, you must open the Property Overrides dialog box for the device filter and set the property to "Please enter a text string:".
An alternative way to remove overridden property values is to delete the property override directly in Source view.