In Marg Software, there is no need for the user to exit from the Purchase bill window in order to change bill calculation. The user can easily change the calculation of bill at the time of creating the purchase bill by following the below steps:

• Firstly, the user will press 'Page Up/Ctrl+R/Alt+E' on it.

• Suppose press 'Page Up' key.

• Then the cursor will move to the party name name.

•  Press 'Enter' on it.

• A 'Change' window will appear.

• In 'Bill Calculation' option, the user can change the bill calculation as per the requirement.

• Suppose Change with '9'.

• Then press 'Page down' to save the changes.

After following the above steps, the user can change the bill calculation at the time of creating purchase bill in Marg Software.