Need help with product coding

[almannai]

I'm creating a vb product and having this scenario which i don't know how to do it.

In the product there is two textbox options that the administrator can alter their values. The first box got a values like 3,4,7,...,100 and the second can take any integer number like 2.

A variable x in the product should start with the first number in the first textbox which is 3. The second textbox represent a time in hours where each time the system time elapsed that time the variable x will jump to the next value of the first textbox which is 4 in the example above and so on until it reaches 100 then it will get back to value 3.

regards,