<div id="ts1" class="ta1">
Привет
</div>
<input id="push" type="button" value="Нажми меня"/>
<script>
var knopka = document.getElementById ('push');
knopka.addEventListener('click',func1);
knopka.removeEventListner ('click',func1);
knopka.addEventListener('click',func2);
function func1() {
var shadow = document.getElementById ('ts1');
shadow.style.display="none";
};
function func2() {
var shadow = document.getElementById ('ts1');
shadow.style.display="block";
};
var knopka = document.getElementById ('push');
knopka.addEventListener('click',func1);
function func1() {
var shadow = document.getElementById ('ts1');
if (shadow.style.display !== 'none'){
shadow.style.display="none";
}else{
shadow.style.display="block";
}
};
<input id="push" type="button" value="..." onclick="document.getElementById('ts1').classList.toggle('hidden');"/>