sms website psuedo-code

I'm developing a sms website on my server and i would like to know if the following is a good way to go about it:
( i already have a cdma modem connected to my server's com port which will send out the messages over the mobile network to a mobile device)

outgoing messages (website to phone):
1.collect message and phone # from asp form.
2. use vb script (and Activex Dll- MSComm) to open the com port and send to the modem.
(if i use this method will i get problems if many users send messages at the same time?)

OR:

1. collect message and phone # from asp form.
2. save to database.
3. have vb application (running on server) to poll database for new entries. when it detects a new entry - grab it, then open a com port and send to the modem.
(if i use this method is it possible to get a vb application to consistently poll a database for new entries?)

thanks.

sam