Help with g77 (DESPERATELY)

[Karenstewart2@aol.com]

Hi!

My name is Karen and I'm a math and computer science teacher at a small middle school.  I want to introduce my students into computer programming using Fortran 77.  I found on the web free software and downloaded it (called Vfort).  I have keyed a short simple program on it but I don't know how to execute it.  

On the tool bar there is a book labeled as GNU Fortran Compiler. But, the program doesn't give me the option to execute it.  I'm assuming what has happened is this:  the software I'm using for Fortran 77 uses the GNU as the compiler to run the programs but in order to do that I also have to install the GNU compiler software.  

Am I correct? If so, where can I get it?  According to the website, it is free software also but no options for downloading it.

If I'm not correct, do you have a clue of how to execute the program?  (In my days of computer programming we still keyed cards......so I'm a little behind with programming)  Can you help?

Thanks