Don't know what to do?

Sometimes we come to a situation that we can not understand what to do actually. We became worried about it. If it is in computer platform you have nothing to worry because all the settings were given by the default operating system. Suppose, you are working in Photoshop or Microsoft office word. You want to close them but suddenly a  message appear like this-

See, the "Yes" button is active by default because not saving will be harmful for user. He/She can lose any unsaved data. So, if you come to in like any of these situation that you not understand, take the step that given by default. I have come in such situation when i was a user of Ubuntu. I used to click on the message & press the Enter key as the default works in this button.