var tmp = 0 ;
var tmpX = 0;
function sc_dn(b,c){
  if(tmp<document.getElementById(b).scrollHeight-c){
  tmp = tmp + 5;
  document.getElementById(b).scrollTop = tmp;}
}
function sc_up(b){
  if (tmp>0){
  tmp = tmp - 5;
  document.getElementById(b).scrollTop = tmp;}
}

function sc_lf(b,c){
  if(tmpX<document.getElementById(b).scrollWidth-c){
  tmp = tmp + 5;
  document.getElementById(b).scrollLeft = tmp;}
}
function sc_rg(b){
  if (tmp>0){
  tmp = tmp - 5;
  document.getElementById(b).scrollLeft = tmp;}
}
//c presents offset
function sc_start(a,b,c){
x=b;
y=c;
if(a==1){
  timer = setInterval("sc_dn(x,y)",50);}
else if(a==2){
  timer = setInterval("sc_up(x,y)",50);}
else if(a==3){
  timer = setInterval("sc_lf(x,y)",50);}
else{
  timer = setInterval("sc_rg(x,y)",50);}
}
function sc_close(){
  clearInterval(timer);
}