You could also try this:
<input type="submit" name="submitbutton1" value="submit1" />
<input type="submit" name="submitbutton2" value="submit2" />
Then in your default function you call the functions you want:
if( Request.Form["submitbutton1"] != null)
{
// Code for function 1
}
else if(Request.Form["submitButton2"] != null )
{
// code for function 2
}