Programming :: Shell Script That Serves As A Toggle?

I often have a need for an icon on my panel or any place that toggles between two states. Example: click the button once and it turns on the Internet (1), click the button again and it turns off the Internet(2), click the button again and it turns the Internet on again (1).The only way I know is to have a script create and delete a file. If it finds no file, it runs operation 1 and creates a file. If it finds the file, it runs operation 2 and deletes the file.