A mobile terminal and a method of controlling a mobile terminal are provided. The method includes assigning at least a first function and a second function to each of one or more variable function keys and performing a first function assigned to a selected one of the variable function keys when the mobile terminal is in a first operating mode and performing a second function assigned to the selected one of the variable function keys when the mobile terminal is in a second operating mode, while maintaining the functions of non-variable function keys.