function verifyEmail (the_email) {

// VARIABLES

var emailPattern=/^(.+)@(.+)$/ //format user @ domain
var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]" //special chars
var validChars="\[^\\s" + specialChars + "\]" //global validity
var quotedUser="(\"[^\"]*\")" //in case of quotes used "joe sushi"@yahoo.com
var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/ //case of IP domain joe@[123.123.123.10]
var atom=validChars + '+' //atom
var word="(" + atom + "|" + quotedUser + ")" //valid words
var userPat=new RegExp("^" + word + "(\\." + word + ")*$") // structure of the user
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$") // structure of domain

// ANALYSIS

//basic user @ domain
var matchArray=the_email.match(emailPattern) 
if (matchArray==null) {
  alert("Your email format is invalid, please correct it.")
  return false
}

//assign user & domain
var user=matchArray[1]
var domain=matchArray[2]

// user
if (user.match(userPat)==null) {
    alert("The username part of your email address is invalid, please correct it.")
    return false
}

// if domain is IP, validate it
var IPArray=domain.match(ipDomainPat)
if (IPArray!=null) {
    for (var i=1;i<=4;i++) {
      if (IPArray[i]>255) {
          alert("your IP address is invalid, please correct it.")
    return false
      }
    }
    return true
}

// if domain is a word
var domainArray=domain.match(domainPat)
if (domainArray==null) {
  alert("Your domain name contains invalid characters, please correct it.")
    return false
}

//assign domain parts and check for valid extension
var atomPat=new RegExp(atom,"g")
var domArr=domain.match(atomPat)
var len=domArr.length
if (domArr[domArr.length-1].length<2 || 
    domArr[domArr.length-1].length>10) {
   alert("The extension of your domain should be bigger than 2 letters and smaller than 10.")
   return false
}

// Make sure there's a host name preceding the domain.
if (len<2) {
   var errStr="Your email format is invalid, please correct it."
   alert(errStr)
   return false
}

return true;
}