<select id='ex'>
   <option value='Opt1' selected>Opt1</option>
   <option value='Opt2'>Opt2</option> 
   <option value='Opt3'>Opt3 </option>
<select>
<img src="plus-black.png" onclick="addOpt()">

function addOpt()
{
   var option=document.getElementById("ex").selectedIndex;
   alert ("option is: "+ option);
}

<input type='date' id='dueDate' min="2019-10-01" max="2020-12-31">
<img src="calendar-black.png" onclick="addDate()">

function addDate()
{
   var Due=document.getElementById("dueDate").value;
   alert ("option is: "+ Due);
}

<div id='ex2' style='color:Tomato' onclick='changeIt()'>Click ME!<div>

function changeIt()
{
  str="<div id='ex2' style='color:Blue'>";
  str+="I'm Blue now<div>";
  document.getElementById("ex2").outerHTML=str;
}