gui programming ii works just like with buttons gui events often we will want our programs to do something if the user presses certain keydrags something on canvasuses the mouse wheeletc these things are called events simple example the first gui program we looked at back in section was simple temperature converter anytime we wanted to convert temperature we would type in the temperature in the entry box and click the calculate button it would be nice if the user could just press the enter key after they type the temperature instead of having to click to calculate button we can accomplish this by adding one line to the programentry bind'lambda dummy= :calculate()this line should go right after you declare the entry box what it does is it takes the event that the enter (returnkey is pressed and binds it to the calculate function wellsort of the function you bind the event to is supposed to be able to receive copy of an event objectbut the calculate function that we had previously written takes no arguments rather than rewrite the functionthe line above uses lambda trick to essentially throw away the event object common events here is list of some common eventsevent description the left mouse button is clicked the left mouse button is double-clicked the left mouse button is released click-and-drag with the left mouse button the mouse wheel is moved the mouse is moved the mouse is now over the widget the mouse has now left the widget key is pressed the key name key is pressed for all of the mouse button examplesthe number can be replaced with other numbers button is the middle button and button is the right button the most useful attributes in the event object are