Urgent help:drawing arrow mark with lineto

[font=verdana, arial, helvetica][size=2]hello,
in my project i am plottin position of ships on different days on the world map using xml…everything is fine except…am having problems in showing the direction of voyage of the ships can someone suggest me a way way by which i can draw arrow marks on the lines i am drawing using lineto,moveto command so as to indicate the direction of the ship voyage…it is extremely urgent…kindly help…

Thanks in advance[/size][/font]