line renderer anchored to Html element

Hello , i'am trying to create a line renderer anchored to Html element, when the camera rotate, the line change the second point position.
i have successfully created a line in 3D space canvas but it's fixed when i rotate the camera by referring to this example :
https://www.blend4web.com/apps/code_snippets/code_snippets.html?scene=lines

worried how can i achieve this ? can i found some tutorial or directions ?
thank you all

See if this is what you are after. It uses no code. One end of a mesh line is tied to a bone armature and that armature has a bone constraint tied to an empty which is parented to the camera for viewport alignment. An anchor tab is tied to that. Blend and HTML file attached.

it's exactly what i'm after , thank you very much

Hello,

i looked at your blend file, and the only thing i don't understand is how you have made the vertex stick to the cube object. I'am new to blender and everything is not very clear.

Thanks.

Edit : Nevermind, i found what i was doing wrong, i didn't put the bones in pose mode before adding the bone constraint.