hi Hello everyone! I'm using a javascrtip production, press and hold to drag hotspot hotspot on the screen, which in javascript encountered a problem! Code stickers, and friends around the world to help me see it? Here Thank you very much! 
function show_addkrpano(){
krpano.call("addhotspot(hotspot_line);");
krpano.set("hotspot[hotspot_line].url",'./comm_line.png');
krpano.set("hotspot[hotspot_line].ath",krpano.get("view.hlookat"));
krpano.set("hotspot[hotspot_line].atv",krpano.get("view.vlookat"));
krpano.set("hotspot[hotspot_line].zoom",false);
krpano.set("hotspot[hotspot_line].ondown",draghotspot);
}
function draghotspot(){
var get_obj = krpano.get("hotspot[hotspot_line]");
while(?????????????){
var dx = krpano.get("mouse.stagex");
var dy = krpano.get("mouse.stagey");
var screarr = krpano.screentosphere(dx, dy);
krpano.set("hotspot[hotspot_line].ath",screarr.x);
krpano.set("hotspot[hotspot_line].atv",screarr.y);
}
}