function bodyload() {
  calc_obal();
  }
  
function calc_obal() {
  x = document.getElementById('obal');
  y = document.getElementById('body');
  if (x) {
    bw = y.offsetWidth;
    if (bw==0) {
      bw = screen.availWidth;
      }
    if (bw>1004) {
      x.style.width = 1004;
      }
    }
  }