I attempt to disable my specific bootstrap select option using javascript.

I know how to disable normal select option, but when using bootstrap select it just didnt works (its disabled/greyed but i can still choose it)
here jsfidle

<select name=dropdownBranch id=dropdownBranch class=selectpicker data-live-search=true>

  <option value=0>Choose Number</option>

    <option value=1>1</option>

  <option value=2>2</option>

  <option value=3>3</option>

  <option value=4>4</option>

</select>

<select id=pureDropDown>

  <option value=0>Choose Number</option>

    <option value=1>1</option>

  <option value=2>2</option>

  <option value=3>3</option>

  <option value=4>4</option>

</select>

<button onclick=disableDropdown()>disable</button>







function disableDropdown(){

var selectobject;

selectobject=document.getElementById(dropdownBranch).getElementsByTagName(option);

    selectobject[3].disabled=true;



selectobject=document.getElementById(pureDropDown).getElementsByTagName(option);

    for(z=0;z<selectobject.length;z++){

        selectobject[z].disabled=true;

        }



}

i try to remove specific option too and the same case happen (work on normal dropdown but not work on bootstrap select)