JSFiddle - React, Tailwind, and code Playground

HTML

<form name = "myForm" method="post" onsubmit="return validate();"  >

        <table align = "center" bgcolor = "FF6600" cellspacing = "3" cellpadding = "4" border = "1" style="font-family:Comic Sans;vertical-align:center;">
        <caption style="background-color:#FFD700; text-align:left"> <font size="5" color="black">Check Coverage: </font></caption>
            <tr>
                <td class="info">First Name</td>
                <td><input type = "text" name = "first" class="textright">*</td>
            </tr>
            <tr>
                <td class="info">Phone Number</td>
                <td><input type  = "text"  name  = "phone" size="10" maxlength = "12" class="textright" >* (ddd-ddd-dddd)</td>
            </tr>
            <tr>
                <td class="info">Zip Code</td>
                <td><input type  = "text" id="zip" name = "zip1" size ="5" maxlength = "5" class="textright">* </td>
            </tr>
            <tr>
                <td class="size">* - Required Field</td>
                <td>
                    <input type = "button" class="but2" value ="Reset">
                    <input type = "submit" class= "but2"  value ="Check Availability" ></td>
            </tr>
        </table>
</form>

JavaScript

function validate() {
    var zipCodeField = document.getElementById("zip");
    var zipCode = parseInt(zipCodeField.value);
    if (!(63121 <= zipCode && zipCode <= 69999)) {
        alert("Sorry no service");
        zipCodeField.focus();
        zipCodeField.select();
        return false;
    } else {
        return true;
    }
}