hi,One more question:
I know i can use the cursors 1 & 2 to compare 2 values. But How can i see the defference (subtraction operation) between cursor 1 and cursor 2 when they are in different curves in the plot?
I do not fully understand your question.?
You can right click on the plot window and select 'Add Trace' from the drop down menu.
Enter the required plot data in the lower text box, use the plot data shown in the bigger window to create the equation.