function Waqss2_params(param) {

    var PARAM_ID_ARRAY = [
        "chl",
        "tsm",
        "ys",
        "trn",
        "sst"
    ];

    var PARAM_NAMES_ARRAY = [
        "Chlorophyll Concentration",
        "Total Suspended Matter",
        "Yellow Substance",
        "Water Transparency",
        "Sea Surface Temperature"
    ];

    this.onChange = null;

    // Default-Parameter
    this.currentParam = PARAM_ID_ARRAY[0];

    if (contains(PARAM_ID_ARRAY, param)) {
        this.currentParam = param;
    }

    this.setCurrentParam = function(paramId) {

        if (this.currentParam != paramId && contains(PARAM_ID_ARRAY, paramId)) {
            this.currentParam = paramId;
            this.refresh();
            if (this.onChange != null) {
                this.onChange(paramId);
            }
        }
    };

    this.getCurrentParam = function() {
        return this.currentParam;
    };

    this.refresh = function() {
        selectRadioButton("param", this.currentParam);
    };

    this.addRadioButtonWithLabel = function(parent, paramId, paramTxt) {

        var params = this;
        var inputId = "param_" + paramId;

        var input;
        if (navigator.appName == "Microsoft Internet Explorer") {
            // IE hack
            input = createElem("<input type=\"radio\" name=\"param\" value=\"" + paramId + "\" id=\"" + inputId + "\">");
        } else {
            input = createElem("input");
            input.type = "radio";
            input.name = "param";
            input.value = paramId;
            input.id = inputId;
        }

        input.onclick = function() {
            params.setCurrentParam(paramId);
        };

        var label = createElem("label");
        label.htmlFor = input.id;
        label.innerHTML = paramTxt;

        var br = createElem("br");

        parent.appendChild(input);
        parent.appendChild(label);
        parent.appendChild(br);

    };

    this.getParamFromRequest = function() {

        var reqParams = getRequestParameter();

        for (var i = 0; i < reqParams.length; i++) {
            var paramName = reqParams[i][0];
            var value = reqParams[i][1];
            if ("param" == paramName) {
                this.setCurrentParam(value);
            }
        }
    };

    this.init = function() {

        var elemParams = getElem("params");
        if (elemParams == null) {
            return;
        }
        for (var i = 0; i < PARAM_ID_ARRAY.length; i++) {
            var paramId = PARAM_ID_ARRAY[i];
            var paramTxt = PARAM_NAMES_ARRAY[i];
            this.addRadioButtonWithLabel(elemParams, paramId, paramTxt);
        }
        this.getParamFromRequest();
        this.refresh();
    };

    this.init();

}