function validateFileSize(id, maxsize) {             var btnsave = document.getElementById("Button2");             btnsave.disabled = false;             var filepath = "";             var fileupload = document.getElementById(id);             if (fileupload.value.length < 5) { alert('请选择文件！'); return; }             var agent = window.navigator.userAgent;             if (document.all) {                 var isIE7 = agent.indexOf('MSIE 7.0') != -1;                 var isIE8 = agent.indexOf('MSIE 8.0') != -1;                 //IE7和IE8获得文件路径                 if (isIE7 || isIE8) {                     fileupload.select();                     filepath = document.selection.createRange().text;                 }                 //IE6获得文件路径                 else                 { filepath = file.value; }                 //PageMethods.ValidateFile(filepath, maxsize, ieCallBack);                 alert(filepath);             }             if (agent.indexOf("Firefox") >= 1) {                 alert("FF");                 alert(getValue());                 return false;                 if (fileupload.files) {                     var size = fileupload.files[0].fileSize;                     if (size > parseInt(maxsize)) {                         fileupload.parentNode.innerHTML = '<input type="file" name="' + fileupload.name + '" id="' + fileupload.id + '" onchange="disableSave(this);"/> ';                         alert("文件超过大小！");                     }                     else { alert("文件上传成功！"); }                 }             }         }