google不支持window.showModalDialog问题解决方案

This is a `window.showModalDialog()` shim using a modal HTML5 `` element and ECMAScript 6 Generators. It was tested in the latest Google Chrome with the *Enable Experimental JavaScript* flag enabled in `chrome://flags/#enable-javascript-harmony` and in the latest Mozilla Firefox with the *dom.dialog_element.enabled* preference set to *true* in `about:config`. Just include the following HTML code before using `showModalDialog` function: `[removed][removed]`.