The dialog appears when you select Constant Value/Average Value in the Resources box in the Display screen of the chart wizard and click 
to add it to the Show Values box, or select an additional value in the Show Values box and then click 
when you create or modify a chart. It helps you to add additional values to be shown in the chart or modify the existing additional values. It varies according to different value types.
If it is a constant value, options in the dialog are as follows. See the dialog.
Name
Specifies the display name of the constant value.
Value
Specifies the constant value. Its data type must be numerical.
OK
Creates the constant value and closes the dialog.
Cancel
Does not retain any changes and closes the dialog.
Help
Displays this help document.
If it is an average value, options in the dialog are as follows. See the dialog.
Name
Specifies the display name of the average value.
Based On
Specifies a summary or formula field based on which the average value will be calculated.
OK
Creates average value and closes the dialog.
Cancel
Does not retain any changes and closes the dialog.
Help
Displays this help document.
