使用输入字段中的某些条件以HTML格式创建留言簿应用程序

I want to create a guestbook application page in HTML which has 3 fields for the user to input:

1. Name

2. E-mail

3. Message

I wanna make the client check in JavaScript, so below are my snippets of code which I added in the head of the html page.

1. For the Name I need to put a condition so only letters can be entered, no numbers, no special characters, no spaces or empty field, so I made this

   function Validate()
   {
       var x=document.forms["guest"]["email"].value;
       var y=document.forms["guest"]["name"].value;
       var regex=/^[a-zA-Z]+$/;
   
       if( y==null || y=="" || (!y.match(regex)))
       {
           alert("Please enter your Name! ");
           return false;
       }
   

My question is: How can I insert a condition so the name must be bigger than 3 letters?

2. For the e-mail field I made this:

   if(x==null || x=="")
   {
       alert("Please enter your email address!");
       return false;
   }
   var atpos=x.indexOf("@");
   var dotpos=x.lastIndexOf(".");
   
   if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length)
   {
       alert("Not a valid e-mail address");
       return false;
   }
   else
       return true;
   }
   

Here I don`t have any question.

3. For the message field I need to add a condition so the message must be bigger than 10 characters.

Can you help me with that?

Thanks

You should take a look into the length property.

E.g.:

var y=document.forms["guest"]["name"].value;

if(y.length < 3) {
    alert("Not a valid name");
    return false;
}

Further informations for the length property on w3schools

An other option is to use the HTML5 minlength attribute:

<label>Username: <input name=u required minlength=3></label>

Further informations for the minlength attribute on W3

You really dont even need javascript for this:

<form action="">
  <input type="email" pattern="[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,4}$" name="email" required title="Valid email required" required>
  <br>
  <input type="text" pattern="[a-zA-Z]{3,}" name="name" required title="Letters only and at least 4 characters" required>
  <br>
  <input type="text" pattern=".{10,}" name="message" required title="10 characters minimum" required>
  <br>
  <button>Submit</button>
</form>

</div>