var	popUp;

function popup( url, windowname, WIDTH, HEIGHT, scrolling )
{
	var x;
	var y;

	if( popUp && !popUp.closed ) 
		popUp.close();
    /*
	if( document.all ) {
    	x = window.screenLeft;
		y = window.screenTop;
	} else {
		x = window.screenX;
		y = window.screenY;
	}


	x = Math.round( (screen.availWidth - WIDTH) / 2) ;
	y = Math.round( (screen.availHeight - HEIGHT) / 2);
    */
    x=0;y=0;
    
	if( scrolling ) {
	  popUp = window.open( url, windowname,'width='+WIDTH+',height='+HEIGHT+',top='+y+',left='+x+',resizable=yes,scrollbars=yes' );
  } else {
    popUp = window.open( url, windowname,'width='+WIDTH+',height='+HEIGHT+',top='+y+',left='+x+',resizable=no,scrollbars=no' );
  }
	return false;
}