How do you alert a person when the person is leaving the page

Answer 1

alert(); function is used only to give some message to the user. it has only one button 'OK' . Thus if u use alert(); ...u can't prevent user from leaving the page.

instead use confirmation dialog box.
confirm(); returns true if user press 'OK' button and returns false if user press 'Cancel' button.

var val = confirm(" Do you want to leave the page ");

this creates a confirmation dialog box.
thus based on the users input u can continue

Answer 2

Leaving the page? Do you mean something like going to another page? If so, it is simply <a href="http://google.com" onclick="alert("Leaving already?")">

Answer 3

if the cursor is not on the webpage show an alert but only once.
i know you can do it with javascript or jquery.

Answer 4

You could make use of the onunload() event. Reference: http://www.w3schools.com/jsref/event_onunload.asp