Hi niravapa here is the image of the VI. You can get the example of the single write in help >> Find example.
For opening new files you can download the 30 day LabVIEW evaluation
Also you might find intresting this tutorial:
http://zone.ni.com/devzone/cda/tut/p/id/3116
Best Regards
Benjamin C
Principal Systems Engineer // CLA // CLED