N72 Showing"No memory card inserted" with any card

[abhipn]

Hi Abhi here,

I've had my nokia n72 using from last one year. Before few days i've got completely wet in the rain n at the same while my cell is in my jeans' pocket and remained there for near about 2 hours. After that my phone was behaving very abnormally and when i switched it off n then turned it on. In memory card option it was showing "no memory card inserted" then i've inserted my extra memory card n also tried my friends card but the same message was there. After that i've formatted phone once using "3,*,call" hard reset. But it wasn't worked. I think the memory card slot is damaged.
Can anyone plz plz guide me regarding this?
How much it will cost to put a new memory card slot?