d Huewai-E220 usb modem on Ubunto 7.1 and Vodacom

I am a newcomer to Linux so please help with this problem. Have edited wvdial.conf file and have rmmod usbseril and then modprobe usbserial vendor=0x12d1 product=0x1003. ls -f /var/log/messages allows me to see wvdial trying to initiate the modem and failing to link to outside. Can anyone offer any suggestions or help
many thanks
a newbie