[javascript] Hide Button After Click (With Existing Form on Page)

CSS code:

.hide{
display:none;
}

.show{
display:block;
}

Html code:

<button onclick="block_none()">Check Availability</button>

Javascript Code:

function block_none(){
 document.getElementById('hidden-div').classList.add('show');
document.getElementById('button-id').classList.add('hide');
}