need help with car acceleration sound code

I'm working on a car, which is using the arrow keys to accelerate, brake and turn.

I'm trying to set it so that when "up arrow" is pused, to make the car accelerate, an "accelerating engine" sound plays - but as soon as the "up arrow" is released, the car goes back to an "engine idle" sound.

Here's what I have right now:

--------------------------------------

if(level & CONTROL_FWD)

{
cur_wheel_direction = "WHEEL_FORWARD";
llSetVehicleVectorParam(VEHICLE_LINEAR_MOTOR_DIRECTION, <forward_power,0,0> );
reverse=1;
llLoopSound("engine accelerate",1.0);
}
if(~level & CONTROL_FWD)
{
llMessageLinked(LINK_SET, 0, "Wheelstop", NULL_KEY);
llLoopSound("engine idle",1);
}


---------------------------------


My problem: sound is choppy, with loud blasts as it switches from one sound to the other. Further, pressing "down arrow" "left arrow" or "right arrow" keys, causes the idle sound to go into a stuttering loop, as it appears to be rapidly trying to restart from the beginning, over and over again.



Is there a better way to implement tis?

Try this version? This way it only toggled the sound at those instants when the forward control is first pressed or first released, instead of continuously triggering things (since you're using 'level' I assume you're also using the name 'edge' for the other variable ).

if(edge & level & CONTROL_FWD)
{
     cur_wheel_direction = "WHEEL_FORWARD";
     llSetVehicleVectorParam(VEHICLE_LINEAR_MOTOR_DIREC TION, <forward_power,0,0> );
     reverse=1;
     llLoopSound("engine accelerate",1.0);
}
if(edge & ~level & CONTROL_FWD)
{
     llMessageLinked(LINK_SET, 0, "Wheelstop", NULL_KEY);
     llLoopSound("engine idle",1);
}