There are two way to check.first is you can directly check whether key contain A or not in binding like this:-. but i think this is not the better way so instead of this you can use ko.computed to check.
Check for operating system information in Windows 7. 1  Click the Start button , enter Computer in the search box, right-click Computer, and then click Properties. 2  Look under Windows edition for the version and edition of Windows that your PC is running.
Microsoft Download Manager is free and available for download now. This update installs Chinese (Simplified), Chinese (Hong Kong S.A.R.), Chinese (Traditional) and Korean language support files for Microsoft Office Groove 2007 SP1. Note:There are multiple files available for this download.Once you click on the Download button, you will be prompted to select the files you need.