function ventanamapas(){
  lado = document.miforma.modovista.value
  top.window.moveTo(0,0);
  x=800;
  y=600;
  if (document.all) {
     x = screen.availWidth;
     y = screen.availHeight;
     //alert(x);
     //alert(y);
  }else{
    if (document.layers||document.getElementById) {

         x = screen.availWidth;
         y = screen.availHeight;
    }
  }
  if(lado < 500){
     if(x > 800){
        //x = 900;
     }
     if(y > 600){
        //y = 700;
     }
  }

  top.window.moveTo(0,0);
  if (document.all) {
     top.window.resizeTo(x,y);
  }else{
    if (document.layers||document.getElementById) {
         top.window.outerHeight = y;
         top.window.outerWidth = x;
    }
  }
  }

  function go_parent(url){
  opener.location.href=url;
  opener.focus();
  }