<!DOCTYPE html>
<html>
<body>
<p>Click the button to perfom a global search for the letters "ain" in a string, and display the matches.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var str = "The rain in SPAIN stays mainly in the plain";
var res = str.match(/ain/g);
document.getElementById("demo").innerHTML = res;
}
</script>
</body>
</html>