JSFiddle - React, Tailwind, and code Playground

HTML

<script type="text/javascript">

function IsValidZipCode(event) {
		event.preventDefault();
    
    var zip = document.getElementById('txtZip').value;
    var ZipArray = ["60543", "60188"];
    var isValid = ZipArray.indexOf(zip);
    if (isValid >= 0){
       event.preventDefault;
       alert ('Nice! go ahead and book!')
       window.location.href = 'yoururl.com'
    }
    else {
        alert('Sorry, we do not offer delivery here at this time');
        return false;
    }
}
</script>
<form>
Please Enter Zip Code: <input id="txtZip" name="zip" type="number" />
<input onclick="IsValidZipCode(event)" id="Button" type="submit" value="Submit"/>
</form>