LINQ query C#, ASP.NET

Question

String check = Data.Logins.Where(Login=>Login.Username==TextBoxnewusername.Text)

 

I have a table named "Login".

There are 4 columns - Username, password, Name, Address.

The Username column is of data type nvarchar(max).

 

The 'TextBoxnewusername.Text' is a textbox where new users input their user name.

 

Now, the error is as follows-

 

Cannot implicitly convert type 'system.linq.IQueryable<Shop.Login>' to 'String'.

 

Any idea how to correct it?? Is there any casting it?