Script to select all horizontal lines on chart

[General Melchett]

I would like to select all horizontal lines on one chart (so that the small white box appears on either end).

I know I need to use 'OBJPROP_SELECTED' but this isn't referenced much in this forum so I am not sure how I could use it.

I basically want to select all horizontal lines - if they are already selected, then do nothing. If they are not selected, then make them selected (small white box at either end).

[l'andorrà]

@general-melchett I guess that is not possible wiothout custom code. I found no block doing that. I'm interested in the solution to this too.