How do you animate your GUI?

[RicardoQuaresma]

Hello. I am trying to animate a bridge to go up and down. My code is:

Draw.Line(0,137,144,151,black)
Draw.Line(144,151,255,139,black)
Draw.Line(255,139,388,153,black)
Draw.Line(388,153,501,138,black)
Draw.Line(502,138,640,157,black)
Draw.Line(640,157,639,0,black)
Draw.Line(639,2,1,2,black)
Draw.Line(1,2,3,139,black)
Draw.Fill(297,88,11,black)
Draw.Line(103,85,194,92,black)
Draw.Line(193,93,264,72,black)
Draw.Line(483,69,517,85,black)
Draw.Line(517,85,536,66,black)
Draw.Line(384,154,384,234,black)
Draw.Line(384,234,576,234,black)
Draw.Line(576,234,577,148,black)
Draw.Line(384,236,385,323,black)
Draw.Line(384,234,317,235,black)
Draw.Line(317,235,245,275,black)
Draw.Line(261,268,384,311,black)
Draw.Line(385,309,431,188,black)
Draw.Line(431,188,407,171,black)
Draw.Line(385,176,403,175,black)
Draw.Line(403,175,410,173,black)
Draw.Line(410,172,410,172,black)
Draw.Line(410,171,410,171,black)
Draw.Line(410,171,417,153,black)
Draw.Oval(392,166,-5,-5,black)
Draw.Line(56,229,57,150,black)
Draw.Line(56,228,212,228,black)
Draw.Line(212,228,212,147,black)
Draw.Line(212,147,56,145,black)
Draw.Line(57,164,59,148,black)
Draw.Line(55,145,57,159,black)
Draw.Fill(161,195,208,black)
Draw.Line(122,230,122,324,black)
Draw.Line(122,324,168,311,black)
Draw.Line(168,311,123,295,black)
Draw.Fill(-258,457,12,black)