Returns the Function object being executed, that is, the body text of the specified Function object.
The optional function argument is the name of the currently executing Function object.
The callee property is a member of the arguments object that becomes available only when the associated function is executing.
The initial value of the callee property is the Function object being executed. This allows anonymous functions to be recursive.
Supported in the following document modes: Quirks, Internet Explorer 6 standards, Internet Explorer 7 standards, Internet Explorer 8 standards, Internet Explorer 9 standards, Internet Explorer 10 standards. Also supported in Windows Store apps. See Version Information.