A recording medium readable by a computer, tangibly embodying a program of instructions executable by the computer to modify a document including a plurality of areas, a part or all of the plurality of areas including identification, is provided. The program includes the steps of inputting the document, inputting an instruction to the plurality of areas specified by the identification, modifying the document according to the instruction inputted to the plurality of areas specified by the identification, and outputting the document. According to the program, documents slightly different from each other can be created dynamically and easily, by use of a single original document and instructions, and thus productivity of the documents increases.