This post might help you if you want to display alert messages without using tradition javascript (irritating) alert.
To achieve this you need jQuery for your frontend UI.

Below is the javascript method (code snapshot) which displays your message for 5 seconds. And then fades out automatically.

function displayAlertMessage(message) {
var timeOut = 5
jQuery('#messageBox').text(message).fadeIn()
jQuery('#messageBox').css("display", "block")
setTimeout(function() {
jQuery('#messageBox').fadeOut()
jQuery('#messageBox').css("display", "none")
}, timeOut * 1000);
}

messageBox is id of your div tag where you want to display the Alert Message.
timeOut is number of seconds you want to hold message on screen.
That’s it. So simple and quite comfortable from a user’s perspective Isn’t it?

Cheers!!
Salil Kalia