function _getClientWidth() {
  var ret;
  if (self.innerHeight) {
   // IE 외 모든 브라우저
   ret = self.innerWidth;
  } else if (document.documentElement && document.documentElement.clientHeight) {
   // Explorer 6 Strict
   ret = document.documentElement.clientWidth;
  } else if (document.body) {
   // IE Browser
   ret = document.body.clientWidth;
  }
  return ret;
 }
 function _getClientHeight() {
  var ret;
  if (self.innerHeight) {
   ret = self.innerHeight;
  } else if (document.documentElement && document.documentElement.clientHeight) {
   ret = document.documentElement.clientHeight;
  } else if (document.body) {
   ret = document.body.clientHeight;
  }
  return ret;
 }