I need a digits creating and detecting script.

Hi there.

I just found this place. It seems like the place I can get some help on a script I am seeking.

I look for a script that will create a 16 digit code when a button is pushed and save it.
Subsequently, when the code is re-entered in the script it first signals that the code is there or that it is not, and, if the code is present and the go button is pushed the code is processed as used and from then on is absolute: so if re-entered the script gives a negative response.

Is there such a script on the market or how easy is it to code such a script?
And what kind of script coding is this?


Thanks for your help.
Ben