function Filter(elements) {

    /** Extended filter element list. */
    this.xElements = elements;
    
    /**
    *   Clear elemnts.
    */
    this.clearElements = function(elements) {
        if(elements != null) {
            for(var i = 0; i < elements.length; i++) {
                var element = elements[i];
                if(element != null) {
                    element.value = "";
                }
            }
        }
    }

    /**
    *   Clear extra filter elements.
    */
    this.clearXElements = function() {
        return this.clearElements(this.xElements);
    }

}