If you have less time, look for simple file handling source codes. This will help you to save and retrieve data which is entered. Check out some programs using scanf statements for input of the data.

The simple steps:

1) Declare the variables
2) Get the relevant values using scanf into the variables
3) Process the variables to calculate any desired values if required.
4) Use the file handling statements to store the values. File handling requires three steps:
----Open the file
----Write the values to the file
----Close the file

If you were using VB6, then I could have helped you some more.

keep smiling.