Compatible with IE 7, 8

In contentEditable mode, There is a little bug that it will insert result in wrong position.
For example, suppose we are typing @ch and At.js list China for you. After you have choosed that.
At.js will insert this : @chChina.

And, if you have opened the debug console(F12). You can see an warning like this:

HTML1114: Codepage unicode from (UNICODE byte order mark) overrides conflicting codepage utf-8 from (11)

fortunately and great thanks to people rock on stackoverflow, i found the solvation:

http://stackoverflow.com/questions/15535933/ie-html1114-error-with-custom-cleditor-button?answertab=votes#tab-top

so, it seems it is because somethings about cleditor wysiwyg.
And then just add this to header element, and At.js will work fine:

<meta http-equiv="x-ua-compatible" content="IE=Edge"/>