Undefined index in Session variables

Question

I have 3 scripts and I use Session variables to interchange data, so, between 2 of them all works perfectly, but in the third script doesn't recognize any of the Session variables declared before, instead I get the error Undefined index:name_of_variable so, i't like PHP is creating another session, like it was another webpage or something, I don't know. So, is it possible? what should I consider? The third script is code of a library that I'm using.

Answer 1

Try putting session_start(); before the session variable in 3rd script.