function PopUp(w,h,ziel,name)
{
  h = h - 20; var x=0, y=0, parameter="";
  if (w < screen.availWidth || h < screen.availHeight)
  {
    x = (screen.availWidth - w - 12) / 2;
    y = (screen.availHeight - h - 50)  / 2;

    if (x<0)
		x=0;
	  if(y < 0)
	  {
  	 	h = screen.availHeight - 30;
		  y = 0;
	  }
  }

  parameter = "width=" + w + ",height=" + h + ",";
  parameter += "left=" + x + ",top=" + y;
  parameter += ",menubar=no,location=no,toolbar=no,status=no";
  parameter += ",resizable=no,scrollbars=no";

  var Fenster = window.open(ziel,name,parameter);
  if (Fenster) Fenster.focus();
}