Rename an object
When you add an object to the artboard in Microsoft Expression Blend, the object is listed in the Objects and Timeline panel, with brackets [ ] around the object's type; for example, [Image], [Path], or [Ellipse]. When you have multiple objects of the same type in the same window, it can be hard to distinguish each object from others of the same type, unless you give each object a unique name. Additionally, if you plan to reference the object from a code-behind file, the object needs to be renamed
Do one of the following:
With the object selected on the artboard, enter the new name in the Name box of the Properties panel.
In the Objects and Timeline panel, right-click the object that you want to rename, select Rename, and then type the new name.
In the Objects and Timeline panel, click the object that you want to rename, single-click the object again, and then type the new name.