/* 	(stamhankar@hotmail.com)  */
      

function emailCheck (emailStr) {

var emailPat=/^(.+)@(.+)$/

var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"

var validChars="\[^\\s" + specialChars + "\]"

var quotedUser="(\"[^\"]*\")"

var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/

var atom=validChars + '+'

var word="(" + atom + "|" + quotedUser + ")"

var userPat=new RegExp("^" + word + "(\\." + word + ")*$")

var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")

if(emailStr.length==''){
alert("Please enter email adress");
return false;
}
var matchArray=emailStr.match(emailPat)
if (matchArray==null) {
  
	alert("Email address seems incorrect (check @ and .'s)")
	return false
}
var user=matchArray[1]
var domain=matchArray[2]

// See if "user" is valid 
if (user.match(userPat)==null) {
    // user is not valid
    alert("The username doesn't seem to be valid.")
    return false
}

var IPArray=domain.match(ipDomainPat)
if (IPArray!=null) {
    // this is an IP address
	  for (var i=1;i<=4;i++) {
	    if (IPArray[i]>255) {
	        alert("Destination IP address is invalid!")
		return false
	    }
    }
    return true
}

// Domain is symbolic name
var domainArray=domain.match(domainPat)
if (domainArray==null) {
	alert("The domain name doesn't seem to be valid.")
    return false
}

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>3) {
   // the address must end in a two letter or three letter word.
   alert("The address must end in a three-letter domain, or two letter country.")
   return false
}

// Make sure there's a host name preceding the domain.
if (len<2) {
   var errStr="This address is missing a hostname!"
   alert(errStr)
   return false
}

// If we've gotten this far, everything's valid!
return true;
}