A method for displaying an image selected from a plurality of images on a touch screen, comprising steps of: displaying, on the touch screen, at least one image among the plurality of images; each of the plurality of images is associated with different one of consecutive image identification numbers; and the method further comprises steps of: upon detecting a writing operation of a numerical value that is performed by a user on the touch screen while said at least one image is displayed, storing the numerical value in a memory; when a first swipe operation in a first direction on the touch screen is detected after the writing operation, displaying, on the touch screen, one of the plurality of images associated with an image identification number that is equal to an image identification number of said at least one image plus the stored numerical value; and when a second swipe operation in a second direction opposite to the first direction on the touch screen is detected after the writing operation, displaying, on the touch screen, one of the plurality of images associated with an image identification number that is equal to the image identification number of said at least one image minus the stored numerical value. displaying, on the touch screen, at least one image among the plurality of images; each of the plurality of images is associated with different one of consecutive image identification numbers; and the method further comprises steps of: upon detecting a writing operation of a numerical value that is performed by a user on the touch screen while said at least one image is displayed, storing the numerical value in a memory; when a first swipe operation in a first direction on the touch screen is detected after the writing operation, displaying, on the touch screen, one of the plurality of images associated with an image identification number that is equal to an image identification number of said at least one image plus the stored numerical value; and when a second swipe operation in a second direction opposite to the first direction on the touch screen is detected after the writing operation, displaying, on the touch screen, one of the plurality of images associated with an image identification number that is equal to the image identification number of said at least one image minus the stored numerical value. upon detecting a writing operation of a numerical value that is performed by a user on the touch screen while said at least one image is displayed, storing the numerical value in a memory; when a first swipe operation in a first direction on the touch screen is detected after the writing operation, displaying, on the touch screen, one of the plurality of images associated with an image identification number that is equal to an image identification number of said at least one image plus the stored numerical value; and when a second swipe operation in a second direction opposite to the first direction on the touch screen is detected after the writing operation, displaying, on the touch screen, one of the plurality of images associated with an image identification number that is equal to the image identification number of said at least one image minus the stored numerical value.