<!DOCTYPE html>
<html>
<body>
Search: <input type="search" id="mySearch"><br><br>
<button onclick="disableBtn()">Disable Search Field</button>
<button onclick="undisableBtn()">Undisable Search Field</button>
<script>
function disableBtn() {
document.getElementById("mySearch").disabled = true;
}
function undisableBtn() {
document.getElementById("mySearch").disabled = false;
}
</script>
</body>
</html>