/**
 * @author practica
 */
function mail(email){

	var mail = email.value;
	var patron=/^[A-Za-z][A-Za-z0-9_\-\.]*@[A-Za-z0-9_]+.[A-Za-z0-9_.]+[A-za-z]$/;
		if ((mail.length == null ) || (mail.match(patron)))
      		return false;
   		else
    		return true;
	
}