Change speed of animation using code

• Created an animation for a rectangle that either goes up or down.
• Is it possible to change the speed of the rectangle only when it is going up by using code?
• Below, is the code for the button:

if(sym.getComposition().getStage().getSymbol("rect").upDown == 0){

sym.getComposition().getStage().getSymbol("rect").upDown = 1;

sym.getComposition().getStage().getSymbol("rect").playReverse();

}

else{

sym.getComposition().getStage().getSymbol("rect").upDown = 0;

sym.getComposition().getStage().getSymbol("rect").play();

}

Thanks,

Eddie