connection string problems

Hi , I have so many problems with database.
I changed my connection string on my web config -
but when I wanna enter to a page with database gridview I have error -
"the connection name 'Data Source=tcp:s01.Winhost.com;Initial Catalog=DB_7405_drushim;User ID=DB_7405_drushim_user;Password=******;Integrated Security=False' was not found in the applications configuration or the connection string is empty."
I tried to change the gridview connection but it's not working.
what can I do ? how can I know what's the connection string gridview?
or maybe I don't have to change ?
thanks

 

What is the URL so we can see the error?

 

PROBLAMS with database

OK , at the end I succeed connect to database .
I hope I wizard my sql file to Winhost .....
It's working , I can see the gridview and the details inside the gridviw but I can't add things to the table (gridview).
when I use visual studio I can add, but when I try to use from the site I have a problam , do you have any idea what it can be ?
I really don't know what to do ?

 

I forgot to say that I use Linq to SQL and dbml file .
Maybe I have to do something with this?

 

We still don't have enough information to solve this problem. Do you have a link we can test out?