System Dialogs in javascript - alert, confirm, and prompt

//System dialogs
//1. alert
alert('Hello jsfiddle.net');


//2. confirm - with ok and cancel button ok button for the if is true case and cancel button for the else case 
if(confirm('Do you want to leave this page?')){
 console.log('You chose to leave the page.');
}
else{
 console.log('You chose to stay on the page.');
}

//3. prompt - with an ok and a cancel button
var input = prompt('Enter Your address please!');
if(input != null && input != '')
 console.log(input);
else
{
 console.log('You did not enter any address');
}