How to remove event listener on layout separator

[chang]

I want to change the separator to button and remove the separator mousedown event listener.

I try this.

1. document.getElementsByClassName(“dhxlayout_sep dhxlayout_sep_resize_v”).onmousedown = “”;
2. document.getElementsByClassName(“dhxlayout_sep dhxlayout_sep_resize_v”).removeEventListener(‘mousedown’,_doOnMouseDown);
3. $(“.dhxlayout_sep”).off(‘mousedown’);
4. $(“.dhxlayout_sep”).unbind(‘mousedown’);

is don’t have The mousedown event function name?
how I can remove the separator event listener?