Hi.
If you using MSCOMM control
Use CommPort properties.
Set this properties to value from 1 to 16. If port does't exist MSCOMM control generate error "Device unavailable". Catch this error and go ahead.
Denis.

>In past days George Tasker sent a nice code to dialing phone.
>
>The port is assigned by hand. How may I detect the communication port automatically?
>
>Thanks.
>
>Alejandro Fernandez