I seen a post like this already but I am still lost when it comes to trying to put in a required field into one of my forms. Could someone please help. I am so lost.

Here is a type of form I use and would like to learn how to add required fields to my coding.


<style type="text/css">
<!--
.style1 {color: #FFFFFF}
.style2 {
font-family: Tahoma;
font-size: 12px;
}
.style3 {color: #FF0000}
.style10 {
font-size: 12px;
font-style: italic;
}
.style11 {font-size: 14px}
.style12 {
font-style: italic;
font-weight: bold;
font-family: Tahoma;
font-size: 12px;
}
.style15 {
font-size: 16px;
font-weight: bold;
}
.style21 {font-family: Verdana, Arial, Helvetica, sans-serif}
.style22 {
font-family: Tahoma;
font-weight: bold;
color: #FF0000;
}
.style23 {font-family: Tahoma}
.style25 {font-size: 16}
-->
</style>
<script language="JavaScript" type="text/JavaScript">
<!--
function MM_reloadPage(init) { //reloads the window if Nav4 resized
if (init==true) with (navigator) {if ((appName=="Netscape")&&(parseInt(appVersion)==4)) {
document.MM_pgW=innerWidth; document.MM_pgH=innerHeight; onresize=MM_reloadPage; }}
else if (innerWidth!=document.MM_pgW || innerHeight!=document.MM_pgH) location.reload();
}
MM_reloadPage(true);
//-->
</script>
<span class="style2"> <br>
<span class="style15"><span class="style21">Contact Seller</span></span> <br>
<br>
Your Name:</span></span><span class="style10"><span class="style3"></span></span><em><span class="style3">*</span></em><br>
<input type="text" name="Name">
<br>
<span class="style2">Your Phone No.:</span><span class="style3">*</span><br>
<input type="Phone" name="Phone_no.">
<br>
<span class="style2">Your e-mail:</span><span class="style3">*</span><br>
<input type="Phone" name="e-mail.">
<br>
<span class="style2">Car details (Year, Make, Model, Price):</span><span class="style3">*<br>
<SPAN class=style2><strong>(Example:</strong> 2004 BMW 320D - &pound;6700</SPAN>)</span><br>
<input type="Phone" name="CarDetails" size="34">
<br>
<br>
<span class="style2">Questions:</span><em><span class="style3">*</span></em> <span class="style11"><em><span class="style12"> </span></em></span><br>
<textarea name="Message" cols="33" rows="5"></textarea>
<span class="style11"><em><span class="style12"> </span></em></span><br>
<br>
<span class="style11"><em><span class="style12">
Note: <span class="style3">*All fields are required!</span></span></em></span> <span class="style11"><em><span class="style12">
<input name="Submit" type="submit" value="Send" />
</span></em></span><br>
<span class="style1">

</span>
</p>
</form>
</form>