A context menu including a group copy function is displayed and, when the function is selected, all parent nodes of a node corresponding to the input field the pointing device is positioned over are displayed as alternatives to be copied. In response to selection of a parent node for copying by the pointing device, data in all nodes lower than the parent node are copied into a memory. In response to clicking by the pointing device in the input field selected as a pasting destination, a data type of the input field selected as the copying destination and the data type of the data copied into the memory are compared, and if the same, all of the data copied into the memory are pasted in the fields lower than the input field previously selected as the pasting destination.