Sitecore dialog does not open

Sitecore dialogs are not working with Chrome 37 or above

I was working on sitecore upgrade from 6.3 to 7.2, then I reached to sitecore 7.0 rev.130424. The upgrade process was completed successfully for this step, but I found an issue while I was trying to open the "Index Manager" dialog in sitecore 7.0 rev.130424.

The sitecore upgrade documentation requires you to rebuild the indexes once you have done from 7.0 upgrade. "The ContentSearch indexes must be built before you can take advantage of the Item Buckets and search features. This is done via the following wizard: Sitecore » Control Panel » Indexing » Index Manager." . That was the reason that let me caught this issue in sitecore.

In Short, the index dialog is not the only dialog that it's not working, I checked sitecore logs, But I didn't find any there. I checked the browser console, then I found that there is an error logged there, as the following:

Uncaught ReferenceError: showModalDialog is not defined  

Capture

It's obvious from the error above that the object showModalDialog is not defined, Its a JavaScript error.

After searching about this issue, I found that Google Chrome disabled the API showModalDialog, as they announced that:

"showModalDialog is a bad API that we deprecated earlier this year, and in Chrome 37 we will disable support for it by default.
showModalDialog was first introduced in Internet Explorer 4 and although it was never formally standardized, over time most other browsers added support for it. It allows applications to show a dialog of HTML content that freezes all other content while showing. showModalDialog is not a commonly used API: based on our usage counters, less than 0.006% of pages use it."

http://blog.chromium.org/2014/07/disabling-showmodaldialog.html

Sitecore provides two soultions for this issue:
1- Upgrade your solution to Sitecore CMS 7.1
2- Install a patch for this issue.

If you want to stay with sitecore 7.0, Then you have to install the following patch from sitecore, and everything will work correctly.

Sitecore.Support.416400 (7.0).zip