How can I do auto login to web page using VB?

Exactly what my first idea was. Here's an example of what the HTML will look like:
<FORM METHOD=POST ACTION="www.hotmail.com">
<INPUT NAME="Username" TYPE="TEXT" COLS="7" SIZE="15" VALUE="myusername">
</FORM>

see, the value is the username. i really dont know how you'd make the submit button automatically push, but that's how you'd make the text boxes get assigned.