gistfile1.txt

function email(email) {
    if(typeof email !== "undefined"){
           let lastAtPos = email.lastIndexOf('@');
           let lastDotPos = email.lastIndexOf('.');

           if (!(lastAtPos < lastDotPos && lastAtPos > 0 && email.indexOf('@@') == -1 && lastDotPos > 2 && (email.length - lastDotPos) > 2)) {
              formIsValid = false;
              return console.log("Email is not valid");
            }
            return console.log('valid')
       }  
}