MultiHandleSlider in a WebUser

Hello,

I'm trying to create a WebUser MultiHandleSlider Indoor.

I have a MultiHandleSlider into a WebUser, and I create several WebUser controls.

Unfortunately I am creating a bug

"Erreur d’exécution JavaScript: Sys.InvalidOperationException: Two components with the same id 'MultiHandleSliderExtenderAnneeDeNaissance' can't be added to the application."

I do not know why but MultiHandleSlider control is the only to have this problem.

I try to change the ID in code but it gives me always the same error.

Control ctrlSlider = this.FindControl("MultiHandleSliderExtenderAnneeDeNaissance");

if (ctrlSlider != null && ctrlSlider.GetType() == typeof(MultiHandleSliderExtender))
{
     MultiHandleSliderExtender slider = (MultiHandleSliderExtender)ctrlSlider;
     slider.ID = this.ID + "_MultiHandleSliderExtenderAnneeDeNaissance";
}

If someone has an idea thank you in advance.