return ta;}
function trackDocument(stateObj,movefn,upfn){stateObj.movefn=movefn;stateObj.upfn=upfn;document.addEventListener('mousemove',movefn);document.addEventListener('mouseup',upfn);}
function untrackDocument(stateObj){document.removeEventListener('mousemove',stateObj.movefn);document.removeEventListener('mouseup',stateObj.upfn);stateObj.movefn=null;stateObj.upfn=null;}