make div text disappear after 5 seconds using jquery?

$.doTimeout( 5000, function(){ 

 // hide the div
}); 

You can use empty() to remove a <div> contents:

setTimeout(fade_out, 5000);

function fade_out() {
  $("#mydiv").fadeOut().empty();
}

assuming:

<div id="mydiv">
  ...
</div>

You can do this with an anonymous function if you prefer:

setTimeout(function() {
  $("#mydiv").fadeOut().empty();
}, 5000);

or even:

var fade_out = function() {
  $("#mydiv").fadeOut().empty();
}

setTimeout(fade_out, 5000);

The latter is sometimes preferred because it pollutes the global namespace less.

You can try the .delay()

$(".formSentMsg").delay(3200).fadeOut(300);

call the div set the delay time in milliseconds and set the property you want to change, in this case I used .fadeOut() so it could be animated, but you can use .hide() as well.

http://api.jquery.com/delay/