I disagree, but the solution to increase the file size in php.ini or .htaccess won't work if the user sends a file larger than allowed by the server application.
I suggest validating this on the front end. For example:
$(document).ready(function() {
$ ('#your_input_file_id').bind('change', function() {
var fileSize = this.files[0].size/1024/1024;
if (fileSize > 2) { // 2M
alert('Your custom message for max file size exceeded');
$('#your_input_file_id').val('');
}
});
});