Hello Prakash,
When your account is created and necessary settings are made, the next step is to make correct configuration settings in your shopping cart. For this go to Administration > Orders > Payment System, select PayPal and click the ‘Edit System’ link. Then, fill the general fields if necessary as described in the our ViArt online manual
http://www.viart.com/paypal_configuration_settings.html
In the parameters list, please specify your business email address where it says 'your.paypal@email.address' and specify value for 'at' (identity token) parameter from your PayPal settings.
If you don't want to pass data to PayPal in multicurrencies please specify a preferred currency code like 'USD' for the currency_code parameter.
With kind regards,
ViArt Support Team