I am trying to log in to gmail on my bold bb....then am supppose to feel my username and password.but I cant get the cursor to enter the box whereI can enter my name...also, can the track ball be pressed inward to click???

yes thats what the trackball is supposed to do.
you click it down, like a mouse to enter things.

Now, the situation is, its not working when I press it downward, I still cant click on web page to put username. WHAT SHOULD I DO??? IS THERE ANY ALTERNATIVE KEY FOR THIS FUNCTION LIKE SHORTCUT, OR HOW DO I CLICK INSIDE OF A USERNAME BOX TO FILL MY NAME ON A WEB PAGE.

What website are you trying to log in to?
I'll see if Im able to click in the username box.