var y = miLineY(p);
    drawMergeLine(x0,y,x1,null);
    var x = p.x + (p.r<rail ? node.w : -mArrow.w);
    var cls = "arrow merge " + (p.r<rail ? "l" : "r");
    drawBox(cls,null,x,y+(mLine.w-mArrow.h)/2);
  }
  function drawNode(p, btm){
    if( p.bg ){
      var e = document.getElementById("mc"+p.id);
      if(e) e.style.backgroundColor = p.bg;
      e = document.getElementById("md"+p.id);
      if(e) e.style.backgroundColor = p.bg;
    }
    if( p.u>0 ) drawUpArrow(p,tx.rowinfo[p.u-tx.iTopRow],p.fg);
    var cls = node.cls;
    if( p.mi.length ) cls += " merge";
    if( p.f&1 ) cls += " leaf";
    var n = drawBox(cls,p.bg,p.x,p.y);
    n.id = "tln"+p.id;
    n.onclick = clickOnNode;