code: function setFloating(){
          var toobarBoxPos = domUtils.getXY(toolbarBox),
              origalFloat = domUtils.getComputedStyle(toolbarBox,'position'),
              origalLeft = domUtils.getComputedStyle(toolbarBox,'left');
          toolbarBox.style.width = toolbarBox.offsetWidth + 'px';
          toolbarBox.style.zIndex = me.options.zIndex * 1 + 1;
          toolbarBox.parentNode.insertBefore(placeHolder, toolbarBox);
          if (LteIE6 || (quirks && browser.ie)) {
              if(toolbarBox.style.position != 'absolute'){
                  toolbarBox.style.position = 'absolute';
              }
              toolbarBox.style.top = (document.body.scrollTop||document.documentElement.scrollTop) - orgTop + topOffset  + 'px';
          } else {
              if (browser.ie7Compat && flag) {
                  flag = false;
                  toolbarBox.style.left =  domUtils.getXY(toolbarBox).x - document.documentElement.getBoundingClientRect().left+2  + 'px';
              }
              if(toolbarBox.style.position != 'fixed'){
                  toolbarBox.style.position = 'fixed';
                  toolbarBox.style.top = topOffset +"px";
                  ((origalFloat == 'absolute' || origalFloat == 'relative') && parseFloat(origalLeft)) && (toolbarBox.style.left = toobarBoxPos.x + 'px');
              }
          }
      }
docs: ie7模式下需要偏移