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.
1 If you canât install the updates, refer to your computer's help system, contact your IT department, or visit support.microsoft.com for more help. 2  Download the latest supported version of iTunes for your PC from one of the links below. 3  After you click the link, click Download to download the iTunes installer.