createLegend Openlayers

var legendHTML = ""; // ni letak atas sekali as global pastu add kt HTML ko
function createLegend(){

    var legend_query = '?REQUEST=GetLegendGraphic&VERSION=1.0.0&FORMAT=image/png&WIDTH=20&HEIGHT=20&LAYER=';
    var layerList = map.frameState_.layerStatesArray;
    for(var i=0; i<layerList.length; i++){
        //console.log(map.frameState_.layerStatesArray[i]);
        if(layerList[i].visible){

            // console.log(layerList[i].layer.values_);
            // console.log(sourceLayer.params_);
            var sourceLayer= layerList[i].layer.values_.source;
            if(typeof sourceLayer.url_ === 'undefined' ){

            }else{
                var legendtitle = layerList[i].layer.values_.title;
                var layerurl = sourceLayer.url_;
                var layerparam = sourceLayer.params_;

                // console.log(layerparam);
                var imglegend = encodeURI(layerurl+legend_query+layerparam.LAYERS);
                legendHTML += "<div class='imglegend'><span>"+legendtitle+"</span>";
                // sini ko boleh control css die guna .imglegend>span or yg mana ko rase senang
                legendHTML += "<img src='"+imglegend+"'>";
                legendHTML += "</div>";
            }
        }
    }
}