USB CDC on LPC17XX

Hello!

I need to send arrays of data over the USB to PC with use of USB-CDC example offered by KEIL (LPC1768). The code goes something like that:

unsigned char dataToSend[] = {'L','E','O','S','S','\n','\r'};
while(Cnt < 5)
{
        USB_WriteEP (CDC_DEP_IN, (unsigned char *)&dataToSend[0], 7);
        Cnt++;
}

As I understand I do the overrun on CDC_DEP_IN. Is there a way to see if the EP is busy? Or even better is there a way to form a Interrupt when CDC_DEP_IN finishes transmitting?

Thanks for the help!