function popwin(img, zw, zh)
{
    var generator=window.open('','name', 'height='+zh+' ,width =' + zw);
  
    generator.document.write('<html><head><title>Weather</title>');
    generator.document.write('</head><body style="margin:0;padding:0;>');
    generator.document.write('<div align="center" id="zoomimg"><img src="'+img+'" border="0"></div>');
    generator.document.write('</body></html>');
    generator.document.close();
}
