숫자 콤마 찍기 (3자리마다)

function number_string(val) {

 var len, strb, revslice;

 strb = val.toString();

 strb = strb.replace(/,/g, '');

 strb = getOnlyNumeric(strb);

 strb = parseInt(strb, 10);

 if(isNaN(strb)) return '';

 strb = strb.toString();

 len = strb.length;

 if(len < 4) return strb;

 gan = 3;

 count = len/gan;

 slice = new Array();

 for(var i=0; i<count; ++i) {

  if(i*gan >= len)

   break;

  slice[i] = strb.slice((i+1) * -gan, len - (i*gan));

 }

 revslice = slice.reverse();

 return revslice.join(',');

}