JSFiddle - React, Tailwind, and code Playground

HTML

<script>
function validateForm() {
    var re = /^(\+0?1\s)?\(?\d{3}\)?[\s.-]\d{3}[\s.-]\d{4}$/; 
    var phone1 = document.forms["myForm"]["phone"].value;
    var m = re.exec(phone1);
    if (m && m[0]){
        return true; 
    }else{
        alert("Please enter a valid phone number");
        return false;
    }
 }
</script>
<form name="myForm" onsubmit="return validateForm()" method="post">
    <label for="phone">Phone:</label>
    <input name="phone" id="phone" value="" placeholder="Zip..." type="text" onsubmit="return validateForm()" />
    <button type="submit">Submit</button>
</form>