how to disable DIV element and everything inside

The following css statement disables click events

pointer-events:none;

pure javascript no jQuery

function sah() {
		$("#div2").attr("disabled", "disabled").off('click');
		var x1=$("#div2").hasClass("disabledDiv");
		
		(x1==true)?$("#div2").removeClass("disabledDiv"):$("#div2").addClass("disabledDiv");
  sah1(document.getElementById("div1"));

}

    function sah1(el) {
        try {
            el.disabled = el.disabled ? false : true;
        } catch (E) {}
        if (el.childNodes && el.childNodes.length > 0) {
            for (var x = 0; x < el.childNodes.length; x++) {
                sah1(el.childNodes[x]);
            }
        }
    }
#div2{
  padding:5px 10px;
  background-color:#777;
  width:150px;
  margin-bottom:20px;
}
.disabledDiv {
    pointer-events: none;
    opacity: 0.4;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.2/jquery.min.js"></script>
<div id="div1">
        <div id="div2" onclick="alert('Hello')">Click me</div>
        <input type="text" value="SAH Computer" />
        <br />
        <input type="button" value="SAH Computer" />
        <br />
        <input type="radio" name="sex" value="Male" />Male
        <Br />
        <input type="radio" name="sex" value="Female" />Female
        <Br />
    </div>
    <Br />
    <Br />
    <input type="button" value="Click" onclick="sah()" />

Try this!

$("#test *").attr("disabled", "disabled").off('click');

I don't see you using jquery above, but you have it listed as a tag.