Client-side file size check
HTML5 file size check and jQuery reset of input element
HTML
<form>
<input id="file" type="file" />
</form>
JavaScript
var maxSize = 1048576; // 1MB
$(function(){
$("#file").change(function(){
var e = $("#file");
var fileSize = e.get(0).files[0].size;
alert(fileSize);
if (fileSize > maxSize){
alert("La dimensione del file ("+fileSize+") supera quella consentita ("+maxSize+")." );
e.wrap('<form>').closest('form').get(0).reset();
e.unwrap();
}
});
});