how to make the form hide using javascript code example

Example 1: html button that hide and show

<button onclick="toggleText()">button</button>
<p id="Myid">Text</p>
<script>
function toggleText(){
  var x = document.getElementById("Myid");
  if (x.style.display === "none") {
    x.style.display = "block";
  } else {
    x.style.display = "none";
  }
}
</script>

Example 2: javascript hide a div

<div id="main"> 
  <p> Hide/show this div </p>
</div>

('#main').hide(); //to hide

// 2nd way, by injecting css using jquery
$("#main").css("display", "none");