JSFiddle - React, Tailwind, and code Playground

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/dot-luv/jquery-ui.css">
<form action="#" method="POST" onsubmit="return valid8(this)">
    
    Email: <input type="text" name="email" size="30" />
    <input type="submit" value="clicky-click" />
    
</form>

JavaScript

var pattern1 = new RegExp("^[0-9a-zA-Z]+@[0-9a-zA-z]+[\.]{1}[0-9a-zA-Z]+[\.]?[0-9a-zA-Z]+$");

function valid8email(field, txt)
{
  with(field)
  {
    if(!pattern1.test(value)) //at_pos < 1 || (dot_pos - at_pos) < 2)
    {
      alert(txt);
      return false;
    }
    else
    {
      return true;
    }
  }
}

function valid8(form)
{
  with(form)
  {
    if(valid8email(email, "you must enter an email address") == false)
    {
      email.focus();
      return false;
    }
  }
}