How to use a variable(may be a static) across projects?

I have 3 projects in the same solution. One of the project has the a static variable, which I am trying to access it in the other two projects(by adding the 3rd project's dll). I see that 2 different copies of the static variables are created in the other 2 projects.

How do I solve this problem and access this static variable and make it only one instance across the 2 projects? I mean once it is modified in one project, it should be reflected in the other project.

Of course you can, and even it's very easy.

Since you've already specify the tag solution, assuming you are developing with Visual Studio is reasonable.

I'm further assuming you are writing in c#, but if you are not, there will be a similar approach to do the same thing.

With c#, in the project you declare the static variable, like

namespace CrossProject {
    public partial class PartialClass {
        public static String StaticVariable="123";
    }
}

And you can access StaticVariable in other two projects by specifying

using CrossProject;

So that you can use it like

Console.Write("{0}", PartialClass.StaticVariable);

It's not necessarily be a partial class, but notice that variable declaration must be in a class scope.