Animation glitching

[Honsly]

I am trying to animate a man's arm moving up and down but it keeps glitching up.

It starts out fine but suddenly it just glitches and i don't know why."
Can someone please take a look at it and figure out why it glitches up. I don't have a clue.

I have pasted the code below to you can look at it and see it for yourself.

Turing:

%----------------------------Body------------------------------------------ drawline (30,0,80,150, black) %Left Leg drawline (80,150,125,0, black) %Right Leg drawline (80,150,80,300, black) %Body drawline (80,300,30,175, black) %Left Arm drawline (80,300,250,300, black) %Right Arm drawfilloval (80,350,50,50, black) %Head %----------------------Moving Arm---------------------------------------- var x : int := 250 var y : int := 300 var a : int := 200 var b : int := 250 loop loop     drawline (80,300,x,y, black) %Right Arm Goes Down     x := x - 1     y := y - 1     delay (10)     drawline (80,300,x + 1,y + 1, 0) %Right Arm Disappears     exit when x = 200    end loop loop     drawline (80,300,a,b, black) %Right Arm Goes Up     a := a + 1     b := b + 1     delay (10)     drawline (80,300,a - 1,b - 1, 0) %Right Arm Disappears     exit when a = 251 end loop end loop

I am using Turing 4.1.1

[Insectoid]

You need to reset your variables at the end of their loops.