Trouble with this programm. Please help!

[Didier Lachieze]

Are you sure you have the latest version of the Prime software?

With version 6975 I have no errors with your program.
Here is what I got:
       

Regarding the variable names in your program I would recommend not to use Global names for local variables as this can be confusing. Having L1 as your program parameter doesn't change the content of the L1 global variable but this is confusing as well as using T, I and N for local variables. I would use lower case names instead of upper case to show the difference.