Chapter ,5 contains instructions for using the disk provided with this book as well as numerous solved sample problems. Before using the software, make a copy of the original and store the master disk in a safe place. It is not necessary to know what the various files on the disk are because the batch files, CASING.BAT and CSGAPI.BAT, allow the user to run the program, as well as to modify existing and to create additional files without remembering names. For completeness, however, basically three groups of files are contained in the ROOT directory: PRICE, LOADS and PROGRAM. There are three P R I C E files with the suffix .CPR (Casing PRice); these are the prices for Lone Star's 7-in. , 9 g-in. s a and 13g-in. casings. Similarly, there are three LOADS files with the suffix .CLD (Casing LoaD), which correspond to the three PRICE files. The P R O G R A M files include two FORTRAN files (CASING3D.FOR and CSG3DAPI.FOR) along with their corresponding EXEcutable files. The FORTRAN files have detailed comments throughout to aid those who wish to know more about the program. Also included in the P R O G R A M are three 'C' files (DESIGN.C, PRICE.C and CSGLOAD.C) along with their corresponding EXEcutable files.