Ventanas emergentes.

[pptavo]

deberias crear una cookie cada vez que aparezca una ventana.. en javascript sería algo por el estilo:

Código:

<script language="javascript">

 // configura:
var popup_url = "http://tusitioweb.com";
var atributos = "width="+screen.width+",height="+screen.height+",scrollbars=1,resizable=1,toolbar=0,location=0,menubar=0,status=0,directories=0";



 cookiesent = Get_Cookie('cookiesent');

if(cookiesent != 1){
// cada 4 horas abrira una ventana
popup();
Set_Cookie( 'cookiesent', 1, 4);
}


function popup(){
  popup_vfmail = window.open( popup_url, "", atributos)

    popup_vfmail.blur() //esto esconde el popup (comentar si se quiere visible)
    window.focus() //esto devuelve el foco a la ventana actual

}
function Set_Cookie( name, value, expires, path, domain, secure )
{
// set time, it's in milliseconds
var today = new Date();
today.setTime( today.getTime() );

/*
if the expires variable is set, make the correct
expires time, the current script below will set
it for x number of days, to make it for hours,
delete * 24, for minutes, delete * 60 * 24
*/
if ( expires )
{
expires = expires * 1000 * 60 * 60 * 24;
}
var expires_date = new Date( today.getTime() + (expires) );

document.cookie = name + "=" +escape( value ) +
( ( expires ) ? ";expires=" + expires_date.toGMTString() : "" ) +
( ( path ) ? ";path=" + path : "" ) +
( ( domain ) ? ";domain=" + domain : "" ) +
( ( secure ) ? ";secure" : "" );
}

function Get_Cookie( check_name ) {
        // first we'll split this cookie up into name/value pairs
        // note: document.cookie only returns name=value, not the other components
        var a_all_cookies = document.cookie.split( ';' );
        var a_temp_cookie = '';
        var cookie_name = '';
        var cookie_value = '';
        var b_cookie_found = false; // set boolean t/f default f

        for ( i = 0; i < a_all_cookies.length; i++ )
        {
                // now we'll split apart each name=value pair
                a_temp_cookie = a_all_cookies[i].split( '=' );


                // and trim left/right whitespace while we're at it
                cookie_name = a_temp_cookie[0].replace(/^\s+|\s+$/g, '');

                // if the extracted name matches passed check_name
                if ( cookie_name == check_name )
                {
                        b_cookie_found = true;
                        // we need to handle case where cookie has no value but exists (no = sign, that is):
                        if ( a_temp_cookie.length > 1 )
                        {
                                cookie_value = unescape( a_temp_cookie[1].replace(/^\s+|\s+$/g, '') );
                        }
                        // note that in cases where cookie is initialized but no value, null is returned
                        return cookie_value;
                        break;
                }
                a_temp_cookie = null;
                cookie_name = '';
        }
        if ( !b_cookie_found )
        {
                return null;
        }
}
</script>