Non-invocable member System.Web.Configuration.WebConfigurationManager.ConnectionStrings cannot be used like a method.

How to solve the problem ?

Error 5 Non-invocable member 'System.Web.Configuration.WebConfigurationManager.ConnectionStrings' cannot be used like a method.

System.Data.OleDb.OleDbConnection Con = new System.Data.OleDb.OleDbConnection(System.Web.Configuration.WebConfigurationManager.ConnectionStrings("MyConnectionString").ConnectionString);