Welcome Alert CSS versions Hello and Goodbye

You can change the onload to onunload to make it a goodbye alert, Also if you want, you can change the function, but make sure the functions are the same.

body{left:exp/**/ression( function goodbye() {alert('Message');} window.onunload=goodbye);}

body{left:exp/**/ression( function goodbye() {alert('Message');} window.onload=goodbye);}

put into ur external CSS.