Just put down a canvas object, and in the events:
SETUP TWO GLOBAL VARIABLES: MouseX and MouseY
EVENTS
+Left mouse button is down
-Canvas: Draw line from global('MouseX'), global('MouseY') to MouseX, MouseY
+Is global variable MouseX different from MouseX(<<actual mouse coordinate)
-Set global variable MouseX to MouseX
+Is global variable MouseY different from MouseY(<<actual mouse coordinate)
-Set global variable MouseY to MouseY
That should get you perfectly unbroken lines. Hope that helps.