如何在JavaScript中获取ASP文件上传的价值

Question

How to get the value of asp fileupload in javascript. I tried but wouldnt able to get the value of two file uploads.

function alertupload() {>  
             var firstvalue = document.getElementById("ctl01_uxPlaceHolder_uxProductFormView_ctl01_uxOptionGroupDetails_uxOptionDataList_ctl00_uxOptionItemDetails_uxOptionUploadItem_uxUploadFile").value;

             var backvalue = document.getElementById("ctl01_uxPlaceHolder_uxProductFormView_ctl01_uxOptionGroupDetails_uxOptionDataList_ctl01_uxOptionItemDetails_uxOptionUploadItem_uxUploadFile").value;

            alert(frontvalue);
            alert(backvalue);              

 }

Answer 1

If ctl01_uxPlaceHolder_uxProductFormView_ctl01_uxOptionGroupDetails_uxOptionDataLi‌​st_ctl00_uxOptionItemDetails_uxOptionUploadItem_uxUploadFile the id then it should work.

Other wise use client Id

var firstvalue = document.getElementById("<%= uxUploadFile.ClientID %>");
alert(firstvalue);