MAPI for email using VB

Hi all,
I wnat to send mail to more than one recipients using VB form with MAPI
function.
For one recipients it is working fine,but for more than one it is not
working. Erro is Undeliverble.
I am using recipients name from VB FORM through single text box.In
which there are Multiple recipients addr.
Basically i Want to send mail to more than one recipients,where email
addresses are taken from textbox in VB Form.

can any body solve this problem?
Thanks
Sujay