function echeck(str) {
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1){
	   return false
	}

	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
	   return false
	}

	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
	    return false
	}

	 if (str.indexOf(at,(lat+1))!=-1){
	    return false
	 }

	 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	    return false
	 }

	 if (str.indexOf(dot,(lat+2))==-1){
	    return false
	 }
	
	 if (str.indexOf(" ")!=-1){
	    return false
	 }
	 return true					
}

function suscribirse() {
  email = $F("email"); 
  
  if ( ((email==null)||(email=="")) || (echeck(email)==false) ) {
     alert('mmmmm... la dirección "'+email+'" no es valida!');
     return false;
  }
  else {
     $("suscripcion").innerHTML = '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img src="img/27-0.gif" alt="suscribiendo...." />';
     new Ajax.Request('suscribir.asp?email='+email, {
        onSuccess: function(transport) 
        {
           alert(transport.responseText);
           $("suscripcion").innerHTML = '<br>&nbsp;&nbsp;&nbsp;&nbsp;<img src="img/bienvenido.gif" alt="hola" />';
        },
        onFailure: function(transport) 
        {
           alert(transport.responseText);
           $("suscripcion").innerHTML = '<input name="email" id="email" value="e-mail"  onfocus="if (this.value == \'e-mail\') { this.value=\'\' }" onblur="if (this.value == \'\') { this.value=\'e-mail\'}" type="text">'+
                                        '<input id="ok" name="ok" type="button" onclick="return suscribirse();" value="ok" />';
        }
       }); 
   }    
}