Untitled

<html>
	<head>
		<title> Check </title>

		<script language="javascript">
			let _list = ['sanjay', 'murali', 'mahesh', 'praveen']

			let f = () => {
				let entered_user = document.getElementById('text_field').value
				let user_present = false
				_list.forEach(x => {
					if (x === entered_user) {
						document.getElementById('text').innerHTML = "User Present"
						user_present = true
					}
				})

				if (! user_present) {
					document.getElementById('text').innerHTML = "User not found"
				}
			}
		</script>
	</head>

	<body>
		<form>
			Enter any name: <input type="text" id="text_field">
			<button onClick="f()" type="button"> Submit </button>
 		</form>

		<p id="text"> </p>
	</body>
</html>