根据xpath  高亮页面元素 

highlight(3,"//img[contains(@src,'adminlogo')]");
 function highlight(times,xpath){
    var flag=true;
    var t = 0;
    var element=document.evaluate(xpath, document, null, XPathResult.ANY_TYPE, null).iterateNext();
    var original_style = element.getAttribute('style');
    var timer=setInterval(
        function(){
            t+=1;
            if(t==times*2+1){
                clearInterval(timer);
                return;
            }
            if(flag){
                element.setAttribute('style', original_style + "background: yellow; border: 3px solid blue;");
                flag=false;
                console.log(flag);
            }else{
                element.setAttribute('style', original_style);
                flag=true;
                console.log(flag);
            }
            
        },500)