Capture simultaneous pressed keys with JavaScript

Question

I want to execute a function when space and right are pressed simultaneous. I tried to achieve this with the following code, but it does not work.

function onKeyDown( event ) {

    if ( scope.enabled === false ) { return; }
    if ( scope.noKeys === true ) { return; }
    if ( scope.noPan === true ) { return; }


    var needUpdate = false;

    switch ( event.keyCode ) {

        case scope.keys.UP:


            camera.position.z -= 1;
            break;
        case scope.keys.BOTTOM:


            camera.position.z += 1;
            break;
        case scope.keys.LEFT:


            camera.rotation.y += 0.1;
            break;
        case scope.keys.RIGHT:              
            camera.rotation.y -= 0.1;
            break;
        case scope.keys.espace:             
            camera.position.y += 50;
            if(camera.position.y > 50){
                camera.position.y -= 1;
            }
            break;
         case scope.keys.espace && scope.keys.RIGHT:
             alert("right and space");
            break;
    }