// logic to control opening and closing of categories
// parse string of category ids into a hash
var openHash = new Object();
var start = 0;
var nextStar = openString.indexOf( '*', start );
while ( nextStar != -1 ) {
    if ( nextStar > start ) 
        var token = openString.substring( start, nextStar );
    openHash[ token ] = 1;
    start = nextStar + 1;
    nextStar = openString.indexOf( '*', start );
}

function openCat( id, url ) {
    openHash[ id ] = 1;
    updateOpenHashAndSend( id, url );
}
function closeCat( id, url ) {
    openHash[ id ] = 0;
    updateOpenHashAndSend( id, url );
}
function updateOpenHashAndSend( id, url ) {
    openString = "";
    for ( ix in openHash ) {
	if ( openHash[ ix ] == 1 )
	    openString += ix + '*';
    }
    var evalString = "window.location.replace( '" + url + "&fl_opn=" + openString + "' );";
    eval( evalString );
}