How to make a DPanel only shows one time ?

[Traziiex]

Hi !

How do I make a code on my server (in this case a derma) only shows up one time (for a specific user), or only shows up if a checkbox is checked ?
I have already done something in the past (with a checkbox), but the issue is that it saved the value Client Side, so if the client was intelligent,
he could change the value to see the derma again. I don't want that to happen !

Example : A first connection welcome Panel

Thank you :D

[editline]14th April 2017[/editline]

I have an Idea of how I should do : Store the steam id of the peoples who checked the checkbox in a textfile, then, when the user join it checks if he did check the checkbox, than if he did : The DPanel doesn not show up.

Is this the true method ?

[dannyf127]

Very simple solution, but not the best. Your text file will work, but you could just use PData.