Nested method calls in UML

[FoX_]

Hi ;
How can I show a nested method call(like getInsertedCourses method below) in a UML sequence diagram ???

static void Main(...)
{
    Student s = new Student(...);
    Course[] courses = s.getInsertedCourses();
}

class Student
{
    private int studentID;
    .......
    public Course[] getInsertedCourses()
    {
         return SRS.getInsertedCourses(this.studentID);
    }
    .......
    .......
}

class SRS
{

    .......
    .......
    public static Course[] getInsertedCourses(int ID)
    {
       ......
       ......
       Courses[] courseArray = .......;
       return  courseArray;
    }
    .......
    .......
}