session_id

my projects is about build a questionnaire,
when user put their quetionnaire data, so i must ive them an unique id..'
how could i give them the id without using session_id.
i like to give an unique id with only number..not '13d4e68'

because, when i'm using session id..i wil return a warning...

You could use the mt_srand() and mt_rand() function for creating the user id itself. If you have access to a database you can use the auto_increment option on a column, which will generate unique id's (it gets incremented, right)



That code above should generate pretty random numbers. I have set up a page where you can test changing the max value of the mt_rand() function. It puts 10 000 values using the mt_rand() function in an array, and then removes the duplicates. It lets you see how many duplicates there are.

http://kbase.webpixels.net/randomnumber.php

Uh, I think that's all I had to say..