function center_fn(경로,창이름,가로크기,세로크기){
     ow= Math.round((screen.availWidth - ww)/2 ); // LEFT
     cw=Math.round((screen.availHeight-hh)/2);
    
     window.open('경로','창이름','width='+가로크기+',height=' + 세로크기 + ',left='+ow+',top=' + cw + ',scrollbars=yes,toolbar=no,location=no,directories=no,status=no,menubar=no,resizable=no,copyhistory=no');
   }


  <a href="#" onclick="center_fn('경로','창이름','가로크기','세로크기');">새창열기</a>