How do you get past the man blocking route 44 in Pokemon heart gold?

The man blocking Route 44 in Pokemon HeartGold is a member of the Team Rocket and he's actually guarding the entrance to the Rocket Hideout.

You can't get past him until you:

1. Defeat the gym leader in Ecruteak City, Morty. This will unlock the entrance to the Rocket Hideout.

2. Enter the Rocket Hideout and defeat all the grunts. This will lead you to the man blocking Route 44.

3. Speak to the man. He will then clear the way for you to proceed on Route 44.

It's important to note that you need to finish the events in Ecruteak City before being able to defeat the man blocking Route 44. This includes completing the gym, the Radio Tower, and the Rocket Hideout.