add to cart ajax not working in joomla 2.5

i have used hikashop and all went fine with joomla 3.2
bt i degraded to joomla 2.5
nw when i click add to cart button popup doesnt appear , instead loads whole pages. thanks

Hi,

Thanks to give us a screenshot of your configuration in Configuration > Main > Cart and Configuration > Display > Main, and a screenshot of the whole page displayed.

In Configuration > Display > Main, you can try to change the popup mode.
Do you have the latest version of HikaShop ?