Adding "use strict;" without any elaboration is the easiest type of comment/reply to make to any perl programming question, and it usually just makes the OPs program die

You seem to have missed that the node in question answers the OP's problem and contains a link to Use strict and warnings.

To always use strict is good advice the same way that to always look both ways when crossing a street is good advice, even when it's a one way street: because it's a good habit to get into. And it might save you some pain someday: https://www.youtube.com/watch?v=0Lm9TPym9A4