Dragging Pie/Bar button over existing button not work due to unconvertible.
Cause:
This problem occurs because the existing format cannot be converted to pie or bar charts. Pie or bar charts need multiple columns of data to create, while the other map formats requires only one column of data.
Solution:
Drag the Pie or Bar Chart button to a blank 'Format' box in the work area, and then drag the desired column headings next to the button to create the pie or bar chart.
1) Click on the Pie or the Bar Chart button on the left side of the dialog box and hold down the mouse button.
NOTE: The pointer changes to a hand-shape tool as soon as it points to a format button.
2) Drag the Pie or the Bar Chart button to a blank 'Format' box in the work area at the right. (The new format button appears in the work area.)
NOTE: A data map can have pie charts or bar charts, but not both.
3) Click on the desired column heading button at the top of the dialog box and hold down the mouse button.
4) Drag the column heading button to the blank 'Column' box next to the format button.
Adding a map format
5) Repeat steps 3) and 4) until the map includes all the desired columns.
NOTE: Up to eight column heading buttons can be added. However, avoid adding too many overlaid formats so that the map does not look cluttered.
