Update With Inner Join Is Not Working

Hi

Please some one help me with this
I have a storedproc

ALTER PROCEDURE [dbo].[usp_updateCustomerList]

(@CustomerID int,
@FirstName varchar(20),
@LastName varchar(20),
@Address1 varchar(35),
@Address2 varchar(35),
@Address3 varchar(35),
@Address4 varchar(35),
@OrderAmount money,
@OrderStatus varchar(6))

as

UPDATE OrderDetails SET Customer.FirstName=@FirstName,Customer.LastName=@LastName,Customer.Address1=@Address1,Custome.Address2=@Address2,Customer.Address3=@Address3,Customer.Address4=@Address4,
OrderDetails.OrderAmount=@OrderAmount,OrderDetails.Status=@Status
From OrderDetails
INNER JOIN Customer
ON OrderDetails.CustomerNumber = Customer.CustomerNumber
where OrderDetails.CustomerID = @CustomerID


When iam executing the stored procedure iam getting error

The multi-part identifier "Customer.FirstName" could not be bound.

Please someone help me with this.

I want to update two tables so ia joining the two tables with customer number which in both the tables.

and customerID is only in OrderDetails table.

so someone please help me with this.

thanks
Ramya