Create drop down list in MS Excel 2010

Creating a drop down list makes it convenient to select from a pre-defined list.
In this case, I am trying to create a drop down list to indicate the Priority i.e. High, Medium and Low.

Drop Down List

Refer to the following link for the instructions:
http://office.microsoft.com/en-us/excel-help/create-or-remove-a-drop-down-list-HP010342357.aspx