The easiest way to add a curve to a 2D diagram is to drag the data set to be displayed as the curve with the mouse from the object list into the diagram. If you use several Y axes, you have to drop the data set onto the Y axis that is to be assigned to the curve.
However, you can also insert an empty curve and then enter the data set manually:
1.If necessary, select the curve in the diagram that you want to use as a template for the new curve. If you do not select a curve, the curve selected as a template on the Curves tab of the Properties dialog box is used.
2.Open the list box under 2D Diagram Design[Diagram Layout] > Add Diagram Element and select Curve.
3.In the dialog box that then appears, enter the data set for the curve. You can also specify separate data sets for the X and Y coordinates of the points of the curve.