◄Up► ◄Next► ◄Previous► ──────────────────────────────────────────────────────────────────────────── include shell.inc VxDcall SHELL_Message The SHELL_Message service displays a message box using the Windows shell. Parameter Description ──────────────────────────────────────────────────────────────────────────── EBX Specifies the handle of the virtual machine responsible for the message. EAX Specifies the message box flags. See the MB_ symbols in the SHELL.INC file. ECX Points to null-terminated string containing the message text. EDI Points to null-terminated string containing the caption text. If this prarameter is zero, the service uses the standard caption. If this parameter points to an empty string, the message box has no caption. ESI Points to the callback procedure to call with response when the message box returns. If this parameter is zero, no callback procedure is called. EDX Specifies reference data to pas to the callback procedure. Return Value The carry flag is clear and the EAX register contains the handle for the event if the service is successful. Otherwise, the carry flag is set to indicate an error such as insufficient memory to display the message. Comments The system calls the callback procedure after the message box is complete. The callback receives the following input parameters: EAX ; response code from the message box EDX ; points to reference data The response code in the EAX register is one of the ID symbols defined in the SHELL.INC file. The EBX register may or may not contain the current virtual machine handle when the callback is called. The callback must not rely on its value. If this service returns an error, a virtual device can use the SHELL_Sysmodal_Message service to force the system to display a message. Uses EAX, Flags ♦