To find ound where php.ini file, is located run this small code

phpinfo();

and search "Configuration File (php.ini) Path " row , there will be an in output window and this which will contain path of php.ini file in your PC

and in this php.ini file, change the variable size as per requirement

upload_max_filesize = (size)M

post_max_size = (size)M

new in php 5

max_input_time = (value) //in second

max_input_time variable which sets a time limit in seconds for receiving input data through POST, GET, and PUT. If your application is running over a slow link,

it is sometimes worthwhile to explore increasing this value to allow the script more time to receive input data. or you can change this variable at run time through programme

example

ini_set('post_max_size','9M')

now post_max_size variable is 9 MB set.

string ini_set ( string varname, string newvalue )

now i added client side validation for restricting user to upload more than particular file size.

use this hidden variable and its value contain how many bytes allow to be upload.

if you want store file in mysql Long blog data type.

set the variable

max_allowed_packet = (byte)

The above steps solved my problem and i can upload big file without any hurdle..