Meta function automatically created by thinBasic engine and valid only inside Callback Functions.
In a Callback Function, return the numeric ID value of the sending the callback message.
id = CBCTL
id = Callback_Control
When a user clicks on a button, types into a text box, or generally interacts with any control in a dialog, Windows sends a message to the callback for the control (or the dialog if the control does not have a callback). CBCTL returns the ID number as assigned to the control with the CONTROL ADD statement.
CBCTL will return the ID of a control if CBMSG = %WM_COMMAND. For other values of CBMSG, CBCTL will return message-dependent values.
This function is only valid inside a Callback Function.