Bella, thanks for your help! Good suggestion.
For example, I have Washington state, Maryland state, Florida state.
The requirement is : ONLY one state is selected, the previous selected state should be de-selected when I selected a new state. For example, I first click Washington state on the map, Washington state will be selected, and then when I click Maryland state, Washington state will be de-selected and ONLY Maryland state is selected.
your suggestion is great: click Washington state to select it, click Washington state again to de-select it; click Maryland state to select it, click Maryland state to de-select it.
The requirement is : click Washington state to select it, click Maryland state and Maryland state is selected and at the same time Washington state is de-select. If we hold Ctrl key when we click the state, we can get the above, but the requirement does not like "holding Ctrl key" either.
Could you please give any suggestion?