diff --git a/error_handling/demo3.go b/error_handling/demo3.go
new file mode 100644
index 0000000..e3bb0d8
--- /dev/null
+++ b/error_handling/demo3.go
@@ -0,0 +1,21 @@
+package error_handling
+
+import "fmt"
+
+type borderException struct{
+	parameter int	
+	message string
+}
+
+func (b *borderException) Error()  string{
+	return fmt.Sprintf("%d ---- %s", b.parameter, b.message)
+}
+
+func GuessIt2(guess int)  (string, error){
+	if guess < 1 || guess > 100{
+		return "", &borderException{guess, "Out of border"}
+	}
+
+	return "You did it", nil
+}
+
diff --git a/main.go b/main.go
index 9ffe7b6..c8a856b 100644
--- a/main.go
+++ b/main.go
@@ -124,4 +124,5 @@ func main() {
 	error_handling.Demo1()
 	interfaces.Demo3()
 	error_handling.Demo2()
+	fmt.Println(error_handling.GuessIt2(102))
 }