Program "Blitz Caller ID Display" — CTI application 3-d party PBX Panasonic KX-TD/KX-TDA, which allows to display the calling number on it or number dial from it on TAPI-interface between PBX Panasonic KX-TD/KX-TDA and on computer of the user of an internal telephone line. The information is given as the liquid crystal display of the PT on the screen of the computer of the user. Calling number at an incoming call from an internal line is determined by PBX under condition that Caller ID function for analog external lines, CLIP or ANI for digital external lines and appropriate complete sets and settings of the PBX are given by the connection operator. The software "Blitz Caller ID Display" is intended: For showing on the display of the computer of numbers of the external and internal subscribers and also names of the internal subscribers at incoming and internal calls on an internal telephone line; For showing on the display status of an internal line; For showing on the display of the computer the information about last incoming and outgoing calls on an internal telephone line. There are two variants of using this program. One is without LAN, another is for LAN. In first variant the computer of the user under OS Windows 98SE/ME/2000Pro/XP is directly connected to PBX Panasonic KX-TD /KX-TDA and TAPI-interface is set between this computer and PBX. Then the CTI application is established on this computer. In second variant computer under OS Windows 2000 Server or Windows 2003 Server is directly connected to the PBX Panasonic KX-TD /KX-TDA, TAPI-interface is set between the computer and PBX and on the basis of it TAPI Server is set. Removed TAPI-client set on name or IP-address of the TAPI Server is connected. Then the CTI application is established on computers of the users.