var a=0; function scrollTop(s) { var b=a+s; document.getElementById('dock').scrollTop=b; a=b; if(b==document.getElementById('dock').scrollHeight) { clearInterval(t); } } function scrollBottom(s) { var b=a-s; document.getElementById('dock').scrollTop=b; a=b; if(b==0) { clearInterval(t); } } function goRight(s) { t=setInterval('scrollBottom(2);',20); } function goLeft(s) { t=setInterval('scrollTop(2);',20); }