A mobile terminal, comprising: a wireless communication unit configured to send an input short text message, wherein a maximum data size of the input short text message is limited; a memory configured to store at least two user data items prepared in advance by a user; a display configured to display the input short text message; an input unit configured to receive the input short text message prior to sending the input short text message; and a controller configured to: select a largest of the at least two user data items having a data size that is a same size or smaller than a remaining data space of the input short text message, and add the selected user data item into a data space of the input short text message in response to a received input; characterized in that the controller is further adapted to: control the display to concurrently display, on a same screen, the input short text message, the selected user data item, and a data size of any remaining data space of the input short text message available for inserting further message input after the selected user data item is added into the data space of the input short text message; and control the wireless communication unit to transmit the input short text message including the added selected user data item as a single short text message. a wireless communication unit configured to send an input short text message, wherein a maximum data size of the input short text message is limited; a memory configured to store at least two user data items prepared in advance by a user; a display configured to display the input short text message; an input unit configured to receive the input short text message prior to sending the input short text message; and a controller configured to: select a largest of the at least two user data items having a data size that is a same size or smaller than a remaining data space of the input short text message, and add the selected user data item into a data space of the input short text message in response to a received input; characterized in that the controller is further adapted to: control the display to concurrently display, on a same screen, the input short text message, the selected user data item, and a data size of any remaining data space of the input short text message available for inserting further message input after the selected user data item is added into the data space of the input short text message; and control the wireless communication unit to transmit the input short text message including the added selected user data item as a single short text message. select a largest of the at least two user data items having a data size that is a same size or smaller than a remaining data space of the input short text message, and add the selected user data item into a data space of the input short text message in response to a received input; characterized in that the controller is further adapted to: control the display to concurrently display, on a same screen, the input short text message, the selected user data item, and a data size of any remaining data space of the input short text message available for inserting further message input after the selected user data item is added into the data space of the input short text message; and control the wireless communication unit to transmit the input short text message including the added selected user data item as a single short text message. control the display to concurrently display, on a same screen, the input short text message, the selected user data item, and a data size of any remaining data space of the input short text message available for inserting further message input after the selected user data item is added into the data space of the input short text message; and control the wireless communication unit to transmit the input short text message including the added selected user data item as a single short text message.