Using web.config credentials

I am using web config to hard code a user for a simple sitye that has one admin user. all works find, but when i put the site live on its public server I get an errer showing that the provider is set in the machine.config to "System.Web.Security.SqlMembershipProvider", So i need to overwrite this in the web.config.
But what do i overwrite it with?, consider the line below what should I change SqlMembershipProvider to
 
<add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembership ...