Why is this query throwing an "Invalid Column Name" error? Trying to run a simple UPDATE query as follows:

UPDATE [TILL].[dbo].[appParameters] 
SET [TILL].[dbo].[appParameters].[ParameterValue] = "1" 
WHERE [TILL].[dbo].[appParameters].[ParameterName] = "StaffTablesRefreshed"


If the field [ParameterName] is the value "StaffTablesRefreshed", then set the value of [ParameterValue] to "1".

When executed, SQL Server throws an error: 


  Invalid column name 'StaffTablesRefreshed'


Both [ParameterName] and [ParameterValue] are nvarchar(255).

Am I missing something obvious here?

Thanks,
Ken
Try replacing the double quotes with single quotes?