Write an Oracle PL/SQL stored procedure named TransferPlayer with the following input parameters:

- p_PlayerID — identifier of the player to transfer.

- p_NewTeamID — identifier of the destination team.

Requirements:

1. Verify that the player exists in the Players table.

2. Verify that the destination team exists in the Teams table.

3. Update the player's TeamID to the new team ID if all validations pass.

4. Raise a meaningful application error if the player or destination team does not exist, or if the jersey number conflicts with another player.

5. Execute the procedure for PlayerID = 501 and p_NewTeamID = 102.