Javascript undefined and empty variable check is a simple yet confusing issue. I have come across this problem couple of times too and finding a proper solution to address it is yet more confusing. Hence, I have summarized it here.

Images can be stored to a MySQL database, in a BLOB datatype. While all other processes of uploading the image is the same as it is to a file, there are couple of error checking that is essential to ensure safety.

OS: Windows Server 2003

1. Download the PHP 5 installer.
Download the latest PHP version for Windows from http://www.php.net/downloads.php

Javascript Functions are chunks of statements of javascript code which exist independently from the main script. These functions are executed only when called.

MooTools is an open source, lightweight, modular object-oriented programming JavaScript web application framework. The MooTools JavaScript framework includes built-in functions for manipulation of CSS, DOM elements, native JavaScript objects, Ajax requests, and more.

My CentOS version is CentOS-5.1

Installing the NTFS kernel Module
First you need to download the NTFS kernel modules rpm from
http://sourceforge.net/project/showfiles.php?group_id=13956&package_id=24313
You should download the version of the kernel module related to your kernel version.

Open the command line, navigate to the directory where MySQL is installed. Further, navigate to the directory 'bin' inside the MySQL directory (in my case, the directory structure is C:\mysql\bin> ) and open MySQL console by entering following command.

Open the command line, navigate to the directory where MySQL is installed. Further, navigate to the directory 'bin' inside the MySQL directory and enter the following command to take the dump of a MySQL database.