HELP Sportline SX HRM and calories burned?

Help me please someone. I bought a Sportline SX today and can't figure out how to figure my calories burned. I know how to get to the screen but it displays the number and a g, which i assume is grams. how do i change to calories or convert or what not. There is also a screen that the manual says is the calorie consumption. What is this screen because the manual does not explain it at all.