The function returns the value of the corresponding chart property. The object property should be of the double type. There are two variants of the function.
1. Immediately returns the property value.
2. If successful, puts the value of property to the specified variable of double type, passed by reference as last parameter.
[in] Chart property identifier (from ENUM_CHART_PROPERTY_DOUBLE enumeration).
[in] Chart subwindow number.
[in] Variable of the double type that received the value of the requested property.
Value of property of the chart assigned to the class instance. If there is not any chart assigned, it returns EMPTY_VALUE.