MessageBoxYesNo - How can I modify?

Does anyone know how to modify the pop up message box from the "Getting Started Tutorial". When the player collects all of the torque objects at the end of the game. The message box pops up and ask "would you like to restart the game"?
"Yes" or "No".

I just want to replace the "loadMyMission" and "quit()" with a link to my mission files. How can I do
this? I'm new to torque. Thanks.

I would like my message box to say "Would you like to go North or South?"
When the player clicks on "North" it takes them to "north.mis". If they click "South", it takes them to "south.mis".

Here's the original "yes or no" code from the "Getting Started Tutorial"

function clientCmdSetScoreCounter(%score)
{
ScoreCounter.setText("Score:" SPC%score);
}

function clientCmdShowVictory(%score)
{
MessageBoxYesNo("You Win!,
"Would you like to restart the game ?",
"loadMyMission();",
"quit();";
}