Wap Push

I studied about Wap Push and i have some doubts about.

Is it possible to send a flash SI or SL message to a phone? I need to send
a message directly on the screen.

>>> Most phones support SI. SL is disabled on many phones due to security reasons.

Is it possible to insert into a SI message an image?

>>> You insert a link to a image.

Is it possible to insert WML code into SI message?
I tested a Nokia 8310

>>> No.

You can send a WAP Push SMS (SI or SL) that triggers the application/image/ringtone download via GPRS.

Most phones today support WAP Push (http://www.visualtron.com) Service Indicator, which will prompt the user whether to download the file, e.g. Java Midlet. The other kind of WAP Push is WAP Push Service Load, which is disabled some models.

A pre-requisite is that the phone user must have GPRS configured and enabled on his mobile.

Rgds,
Joshua