you need to setup CLASSPATH to your JAR file and then you will be able to compile your code simple way

my code is in fold Myfold. the jar file is in another fold c:\programs...

I run javac in c:\myfold.

I need to complie both mycode and the jar code together. Please tell me what I can do.

As I said previously you need to set CLASSPATH to location of JAR file. By doing so you tell your machine where the JAR can be found. So what you do is as follow:
Start > Control Panel > System
here select tab Advanced > Environment Variables
In system variables check if you have CLASSPATH, if not press New
In Variable name : type in capitals CLASSPATH and in Variable value : insert full path yo your JAR file which can be for example like this C:\Development\Custom_lib\swing-layout-1.0.jar;
I would recomend you restart your machine as this changes do not always take place after editing so it is better to restart system. Once this done you can compile your code as simple as this javac mycode.java

You can also set the classpath as a parameter when you execute javac: