function find(id) {
	return document.getElementById(id);
}

INC_VAL = 2;
VEL = 10;

inc = 0;
lpos = 0;
rpos = 0;

function inidespesqarr() {
    inc = INC_VAL;
    despesq();
}

function inidespesqab() {
    inc = -INC_VAL;
    despesq();
}

function findespesq() {
    inc = 0;
    despesq();
}


function despesq() {
  lpos -= inc;
  if (lpos > 0) lpos = 0;
  find("contesq").style.top = lpos;
  if (inc != 0) {
     setTimeout("despesq()", VEL);
  }
}  

function inidespderarr() {
    inc = INC_VAL;
    despder();
}

function inidespderab() {
    inc = -INC_VAL;
    despder();
}

function findespder() {
    inc = 0;
    despder();
}

function despder() {
  rpos -= inc;
  if (rpos > 0) rpos = 0;
  find("contder").style.top = rpos;
  if (inc != 0) {
     setTimeout("despder()", VEL);
  }
}