Hello all, I am trying to take a tradingchart and draw a horizontal line across it. However, I would like the vertical position of the horizontal line to be controlled with a VerticalSlider. I went ahead and asked Chat-GPT and my first attempt was with the following code:

DynamicModule[{linePosition = 6.18}, 
 Column[{Row[{Graphics[{FaceForm[LightGray],EdgeForm[Gray],
       Rectangle[{0,0},{2,10}],(*Rectangle dimensions:width 2,
       height 4*)
       Dynamic@{Dashed, 
         Line[{{0, linePosition}, {2, 
            linePosition}}]} (*Dashed horizontal line*)}
      , PlotRange -> {{0.0, 3}, {0, 10}}
      , ImageSize -> {200, 400}], 
     VerticalSlider[Dynamic[linePosition], {0, 10}, 
      Appearance -> {LeftArrow}, ImageSize -> {Automatic, 400}]}]
   }
  ]
 ]

which simply displays a rectangle and verticalslider and moves a horizontal line up and down based on the slider position.

After having being provided that code, I decided to ask the following question to Chat-GPT:

"In mathematica,I want to create a vertical rectangle with a dashed horizontal line across it whose position is controlled by a vertical verticalSlider on the right side of the rectangle. The verticalSlider must be the same height as the rectangle. The rectangle should be almost transparent as it will have to be displayed on top of a TradingChart with a stock display on it. The rectangle should be the same height as the Tradingchart and on the right of the TradingChart, next to the prices (which are on the right Y axis). Can you please provide code to do so?"

I received the following answer:

Manipulate[
 Show[
  chart, (* chart is a tradingchart displaying a stock *)
  Graphics[{
    FaceForm[Directive[Opacity[0.2], LightGray]],  (* Transparent fill for rectangle *)
    EdgeForm[None], 
    Rectangle[{0.95, 0}, {1.05, 1}], (* Vertical rectangle on the right side *)
    {Dashed, Line[{{0.95, y}, {1.05, y}}]} (* Dashed line controlled by y *)
   },
   PlotRange -> {{0, 1.2}, {0, 1}}, 
   PlotRangePadding -> None, 
   ImageSize -> {Automatic, 400}, (* Matches the height of TradingChart *)
   Background -> None
  ]
 ],
 {{y, 0.5}, 0, 1, 
  Appearance -> "Labeled", 
  ControlType -> VerticalSlider, 
  ImageSize -> {Automatic, 400}, (* Match height of TradingChart *)
  ControlPlacement -> Right}
]

That doesn't work. Can someone help and provide some code?