alert("in");
    var name = document.getElementById("SNameValue").value;
    var email = document.getElementById("SEmailValue").value;
    var emailvalid = /^([a-zA-Z0-9.-]+)@([a-zA-Z0-9-]+).([a-z]{2,5})(.[a-z]{2,5})$/;
    var phoneNum = document.getElementById("SPhoneValue").value;
    var phoneValid = /^(?([0-9]{3}))?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$/;
    var suburb = document.getElementById("SsuburbValue");
    var message = document.getElementById("SMessageValue").value;

    //name validation
    if(name==""){
        alert("Enter your name, please");
        return false;
            }
    //email validation
    if (email==""){
        alert("Enter your email address, please");
        return false;
            }
    if(email.match(emailvalid)){
        return false;
        }
    //phone number validation
    if(phoneNum==""){
        alert("Enter your phone number, please");
        return false;
            }
    if (phoneNum.match(phoneValid)){
        return false;
        } else{
       alert("Enter a valid phone number with 10 digits, please");
       return false;
     }
     //suburb validation
    if (suburb.selectedIndex==0){
        alert("Select your suburb, please");
        return false;
        }
    //message validation
    if(message==""){
        alert("Enter a message, please");
        return false;
        }
    //display everything
    else{
        alert("Name: "+name+"nEmail: "+email+"nPhone number: "+phoneNum+"nSuburb: "+suburb+"Message: "+message);
        return false;
        }
            return true;
}```

HTML code:

``` <form onSubmit="return validate(this)" action="" method="Post">
        Name<br>
        <input type="text" id="SNameValue" placeholder="Enter Name"><br>
        Email<br>
        <input type="email" id="SEmailValue" placeholder="Enter Email"><br>
        Phone Number<br>
        <input type="tel" id="SPhoneValue" placeholder="Enter Phone number"><br>
        Suburb<br>
        <select name="suburbList" id="SsuburbValue">
          <option disabled selected value="">Select your suburb -- </option>
          <option value="Atlantic Seaboard">Atlantic Seaboard</option>
          <option value="Cape Flats">Cape Flats</option>
          <option value="City Bowl">City Bowl</option>
          <option value="Helderberg">Helderberg</option>
          <option value="NothernSuburb">NothernSuburb</option>
          <option value="South Peninsula">South Peninsula</option>
          <option value="Southern Suburb">Southern Suburb</option>
          <option value="West Coast">West Coast</option>
        </select><br>
        Message<br>
        <textarea rows="3" id="SMessageValue" placeholder="How can we help you"></textarea><br>
        <button class="button1" type="submit">Send me a Quote</button>
    </form>