/*
	Include:  CheckEmail.js
	
	Purpose:  Edit and e-mail address string for valid formatting.
	
	Usage:  CheckEmail ( emailStr ).  Returns true if the address is formatted correctly,
	                                  false otherwise.
*/

// this uses the regexp object to validate the e-mail address
function CheckEmail ( 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 +")*$")
	var matchArray=emailStr.match(emailPat)

	if (matchArray==null) {
	  	//sError += "\nEmail 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) {
	    //sError += "\nThe username doesn't seem to be valid.";
	    return false
	}

	// if the e-mail address is at an IP address (as opposed to a symbolic
	// host name) make sure the IP address is valid.
	var IPArray=domain.match(ipDomainPat)
	if (IPArray!=null) {
	    // this is an IP address
		  for (var i=1;i<=4;i++) {
		    if (IPArray[i]>255) {
		        //sError += "\nDestination IP address is invalid!";
			return false
		    }
	    }
	    return true
	}

	// Domain is symbolic name
	var domainArray=domain.match(domainPat)
	if (domainArray==null) {
		//sError += "\nThe 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.
	   //sError += "\nThe 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) {
	   //sError += "\nThis address is missing a hostname!";
	   return false
	}

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