If any one wants to post the payment proof you can follow the steps :-
1. Press the Print Screen/PRTSC button on your keyboard.
2. Go to paint or any other photo editing program and paste the image.
3. Crop the image to remove any private information which you need to keep secret.
4. Save the image on your computer.It is better to save in desktop.
5. Upload the screenshot to an image hosting website such as http://tinypic.com
6. If you uploaded your image to a image hosting website, use the following template to post the image in your Topic.
Any question regarding this can talk with me in chat box or can PM me.