function zoom(img,w,h)
{
	//alert('img:' + img  + ', w=' + w + ', h=' + h);
	var scrollbars = 'no';

	var useDoc = (w > 0 && h > 0);

	if (!w || w < 0) {
		w = 700;
		scrollbars = 'yes';
	}
	if (!h || h < 0) {
		h = 500;
		scrollbars = 'yes';
	}

	var padding;
   (navigator.appName == "Microsoft Internet Explorer") ? (padding = 10) : (padding = 0);


   var screenw = screen.availWidth;
   var screenh = screen.availHeight;

   var maxW = screenw / 100 * 90;
   var maxH = screenh / 100 * 90;

   if ( w > maxW) {
	   scrollbars = 'yes';
	   w = maxW;
   }

   if (h > maxH) {
	   scrollbars = 'yes';
	   h = maxH;
   }


   var winw = (w + 15 + padding);
   var winh = (h + 15 + padding);
   var posx = (screenw / 2) - (winw / 2);
   var posy = (screenh / 2) - (winh / 2);


    if (useDoc) {

    	var features = "top="+posy+",left="+posx+",location=no,menubar=no,resizable=yes,scrollbars=" + scrollbars + ",status=no,toolbar=no,width=" + w + ",height=" + h;
		satellit = window.open("about:blank", "Form", features);
		satellit.window.focus();
		satellit.document.open();
		satellit.document.write("<style>body {margin: 0px}</style><img src='" + img + "' />");
		satellit.document.close();
	} else {
  // -- padding
	  w += 20;
	  h += 20;

	var features = "top="+posy+",left="+posx+",location=no,menubar=no,resizable=yes,scrollbars=" + scrollbars + ",status=no,toolbar=no,width=" + w + ",height=" + h;

		satellit = window.open(img, "Form", features);
		satellit.window.focus();
	}

}

function clearField(obj, initialval)
{
    if (obj.value == initialval) {
      obj.value = '';
    }
}

function popField(obj, initialval)
{
	if (obj.value == '') {
		obj.value = initialval;
	}
}