String Concatenation

create procedure CheckSQLErrors( @TheCode integer, @TheState integer, @Routine varchar(40), @Help varchar(40))
as
begin
{ call LogMsg('SQLA',@Routine,@Help,'sqlstate=' + @TheState +
', sqlcode=' + @TheCode) }
end


I m getting this error.
"Incorrect syntax near + "


+ is used for string concatenation. I tried to use CAST to convert
@TheState and @TheCode variables to varchar but did not work. Can you help me out?



FYI
LogMsg is a sproc

create procedure
dbo.LogMsg( @aAppName varchar(18), @aRoutine varchar(20), @aType varchar(5), @aMsg varchar(255))
as
begin
insert into MessageLog(strAppName,strRoutineName,strType,strMe ssage) values(
@aAppName,@aRoutine,@aType,@aMsg)
end
GO




Thks