A display processing apparatus comprising: a) a connection means connectable to a portable terminal apparatus; b) a transmission means for transmitting screen data for operations of the display processing apparatus to the portable terminal apparatus connected by the connection means; c) a receiving means for receiving from the portable terminal apparatus operation information indicating an operation performed by a user on a remote screen from the portable terminal apparatus displaying in a display means the remote screen of the display processing apparatus based on the screen data, and enlargement display information indicating an enlarged display state when a user operation is performed on a part of the remote screen displayed, with the remaining part of the remote screen missing, in a state in which the screen is enlarged; d) a determination means for determining whether the operation indicated by the operation information received by the receiving means is an operation of displaying a popup portion; and e) a screen generating means for generating next screen data corresponding to the operation information received by the receiving means, and adjusting a display position of the popup portion within the next remote screen that is based on the generated next screen data, so that the popup portion is displayed in the display means of the portable terminal apparatus in an enlarged display state, based on the enlargement display information, so that the user can visually recognize that the popup portion is displayed and can input a numerical value using input keys displayed in the displayed popup portion, if the receiving means receives the operation information and the enlargement display information and if the determination means determines that the operation indicated by the operation information is the operation of displaying the popup portion, and f) wherein the transmission means is configured to transmit the next screen data generated by the screen generating means to the portable terminal apparatus. a) a connection means connectable to a portable terminal apparatus; b) a transmission means for transmitting screen data for operations of the display processing apparatus to the portable terminal apparatus connected by the connection means; c) a receiving means for receiving from the portable terminal apparatus operation information indicating an operation performed by a user on a remote screen from the portable terminal apparatus displaying in a display means the remote screen of the display processing apparatus based on the screen data, and enlargement display information indicating an enlarged display state when a user operation is performed on a part of the remote screen displayed, with the remaining part of the remote screen missing, in a state in which the screen is enlarged; d) a determination means for determining whether the operation indicated by the operation information received by the receiving means is an operation of displaying a popup portion; and e) a screen generating means for generating next screen data corresponding to the operation information received by the receiving means, and adjusting a display position of the popup portion within the next remote screen that is based on the generated next screen data, so that the popup portion is displayed in the display means of the portable terminal apparatus in an enlarged display state, based on the enlargement display information, so that the user can visually recognize that the popup portion is displayed and can input a numerical value using input keys displayed in the displayed popup portion, if the receiving means receives the operation information and the enlargement display information and if the determination means determines that the operation indicated by the operation information is the operation of displaying the popup portion, and f) wherein the transmission means is configured to transmit the next screen data generated by the screen generating means to the portable terminal apparatus.