How to redirect user to payment gateway site in magento?

[yogi]

I want to redirect user to payment gateway when user click "place order" button. as it happen when User uses express paypal for payment. is there any setting in any file or database so that it takes User to payment gateway site, Thank in Advance.
Magento is php framwork for building shopping site
Magento is ecommerce solution to builde shopping sites
http://www.magentocommerce.com/
In this we can set up multiple payment gateways.
I want to redirect user to payment gateways site when user submit order for payment of his order. There is one payment gateways of paypal whos name is "Express paypal" when User choose this option he will get redirected to the paypal site. I want to know where is this setting to redirect user to payment gateway

[x_9th.gate_x]

Im having trouble understanding your english, but paypal usually gives you the option to redirect to a specified page upon payment completion.