Simple healme

function onPlayerCommand( invoker, command, arguments ){
    if( command == "healme" ) //You don't need to put a '/' here.
    {
        if( invoker.Health == 100 ) PrivMessage( invoker, "You already have 100 HP." );
        else {
            invoker.Health = 100;
            MessagePlayer( "INFO: You've 100 HP now.", invoker );
            //This are the 2 functions to send a personal Message( PM ) to a player from the server.
        }
    }
}