UESTC evaluate teaching script

evaluateTeaching.js

(function evaluate(){
    var ifr = document.querySelector('#iframeautoheight'),
        ifrDoc = ifr.contentDocument,
        selects = ifrDoc.querySelector('#DataGrid1').querySelectorAll('.select'),
        i, l,
        options,
        submitBtn = ifrDoc.querySelector('#Button2');

    if( submitBtn.value.search(/提\s*交/) === -1 ){
        for(i = 0, l = selects.length; i < l; ++i){
            options = selects[i].options;
            selects[i].selectedIndex = parseInt(Math.random() * (options.length - 1)) + 1;
        }

        ifr.addEventListener('load', function onIfrLoad(){
            this.removeEventListener('load', onIfrLoad, false);
            evaluate();
        }, false);

        ifrDoc.querySelector('#Button1').click();
    }
    else if(confirm('完成评教了，要提交吗？')){
        submitBtn.click();
    }
})();