function emailCheck (emailStr,pwdStr,loginStr) {

	var myEMailIsValid = true;
	var myAtSymbolAt = emailStr.indexOf('@');
	var myLastDotAt = emailStr.lastIndexOf('.');
	var mySpaceAt = emailStr.indexOf(' ');
	var myLength = emailStr.length;
		
	// at least one @ must be present and not before position 2
	// @yellow.com : NOT valid
	// x@yellow.com : VALID
	
	if (myAtSymbolAt < 1 ) {
		myEMailIsValid = false;
	}
	
	
	// at least one . (dot) afer the @ is required
	// x@yellow : NOT valid
	// x.y@yellow : NOT valid
	// x@yellow.org : VALID
	
	if (myLastDotAt < myAtSymbolAt) {
		myEMailIsValid = false;
	}
	
	// at least two characters [com, uk, fr, ...] must occur after the last . (dot)
	// x.y@yellow. : NOT valid
	// x.y@yellow.a : NOT valid
	// x.y@yellow.ca : VALID
	 
	if (myLength - myLastDotAt <= 2) {
		myEMailIsValid = false;
	}
	
	// no empty space " " is permitted (one may trim the email)
	// x.y@yell ow.com : NOT valid
	
	if (mySpaceAt != -1) {
		myEMailIsValid = false
	}
	
		
	if (myEMailIsValid == true) {
		return true;
	}
	else {
		alert("Votre email n'est pas valide.");
		return false;
	}

}
function pwdCheck (pwdStr) {
var mypwdIsValid = true;
var myLength = pwdStr.length; 
if (myLength < 5){
mypwdIsValid = false;
}
if (mypwdIsValid == true) {
		return true;
	}
	else {
		alert("Votre mot de passe doit comporter au moins 5 caracteres.");
		return false;
	}
}
function loginCheck (loginStr) {
var myloginIsValid = true;
var myLength = loginStr.length; 
if (myLength < 3){
myloginIsValid = false;
}
if (myloginIsValid == true) {
		return true;
	}
	else {
		alert("Votre Identifiant doit comporter au moins 3 caracteres.");
		return false;
	}
}