Ajax File Upload with PHP, HTML5 File API and jQuery

<form action="processupload.php" method="post" enctype="multipart/form-data" id="MyUploadForm">
<input name="FileInput" id="FileInput" type="file" />
<input type="submit"  id="submit-btn" value="Upload" />
<img src="images/ajax-loader.gif" id="loading-img" style="display:none;" alt="Please Wait"/>
</form>
<div id="progressbox" >
<div id="progressbar"></div >
<div id="statustxt">0%</div>
</div>
<div id="output"></div>

$(document).ready(function() {
var options = {
	target:   '#output',   // target element(s) to be updated with server response
	beforeSubmit:  beforeSubmit,  // pre-submit callback
	success:       afterSuccess,  // post-submit callback
	uploadProgress: OnProgress, //upload progress callback
	resetForm: true        // reset the form after successful submit
}; 
 $('#MyUploadForm').submit(function() {
	$(this).ajaxSubmit(options);
	return false;
});
});

function beforeSubmit(){
   //check whether client browser fully supports all File API
   if (window.File && window.FileReader && window.FileList && window.Blob)
	{
        }
        else
	{
	   //Error for older unsupported browsers that doesn't support HTML5 File API
	   alert("Please upgrade your browser, because your current browser lacks some new features we need!");
	}
}

function beforeSubmit(){
   //check whether client browser fully supports all File API
   if (window.File && window.FileReader && window.FileList && window.Blob)
	{
	   var fsize = $('#FileInput')[0].files[0].size; //get file size
           var ftype = $('#FileInput')[0].files[0].type; // get file type
		//allow file types
	  switch(ftype)
           {
            case 'image/png':
			case 'image/gif':
			case 'image/jpeg':
			case 'image/pjpeg':
			case 'text/plain':
			case 'text/html':
			case 'application/x-zip-compressed':
			case 'application/pdf':
			case 'application/msword':
			case 'application/vnd.ms-excel':
			case 'video/mp4':
            break;
            default:
             $("#output").html("<b>"+ftype+"</b> Unsupported file type!");
	     return false
           }
	   //Allowed file size is less than 5 MB (1048576 = 1 mb)
	   if(fsize>5242880)
	   {
	     alert("<b>"+fsize +"</b> Too big file! File is too big, it should be less than 5 MB.");
	     return false
	   }
        }
        else
	{
	   //Error for older unsupported browsers that doesn't support HTML5 File API
	   alert("Please upgrade your browser, because your current browser lacks some new features we need!");
           return false
	}
}

function OnProgress(event, position, total, percentComplete)
{
    //Progress bar
    $('#progressbox').show();
    $('#progressbar').width(percentComplete + '%') //update progressbar percent complete
    $('#statustxt').html(percentComplete + '%'); //update status text
    if(percentComplete>50)
        {
            $('#statustxt').css('color','#000'); //change status text to white after 50%
        }
}

<?php
if(isset($_FILES["FileInput"]) &#038;&#038; $_FILES["FileInput"]["error"]== UPLOAD_ERR_OK)
{
	############ Edit settings ##############
	$UploadDirectory	= '/home/website/file_upload/uploads/'; //specify upload directory ends with / (slash)
	##########################################
	
	/*
	Note : You will run into errors or blank page if "memory_limit" or "upload_max_filesize" is set to low in "php.ini". 
	Open "php.ini" file, and search for "memory_limit" or "upload_max_filesize" limit 
	and set them adequately, also check "post_max_size".
	*/
	
	//check if this is an ajax request
	if (!isset($_SERVER['HTTP_X_REQUESTED_WITH'])){
		die();
	}
	
	
	//Is file size is less than allowed size.
	if ($_FILES["FileInput"]["size"] > 5242880) {
		die("File size is too big!");
	}
	//allowed file type Server side check
	switch(strtolower($_FILES['FileInput']['type']))
		{
			//allowed file types
            case 'image/png':
			case 'image/gif':
			case 'image/jpeg':
			case 'image/pjpeg':
			case 'text/plain':
			case 'text/html': //html file
			case 'application/x-zip-compressed':
			case 'application/pdf':
			case 'application/msword':
			case 'application/vnd.ms-excel':
			case 'video/mp4':
				break;
			default:
				die('Unsupported File!'); //output error
	}
	$File_Name          = strtolower($_FILES['FileInput']['name']);
	$File_Ext           = substr($File_Name, strrpos($File_Name, '.')); //get file extention
	$Random_Number      = rand(0, 9999999999); //Random number to be added to name.
	$NewFileName 		= $Random_Number.$File_Ext; //new file name
	if(move_uploaded_file($_FILES['FileInput']['tmp_name'], $UploadDirectory.$NewFileName ))
	   {
		// do other stuff
               die('Success! File Uploaded.');
	}else{
		die('error uploading File!');
	}
}
else
{
	die('Something wrong with upload! Is "upload_max_filesize" set correctly?');
}