<td width="30%" align="center"> <img src="" id="img["num"]" > </td>"+                  "<td width="60%" align="right">"+                  "<input type="file" id="file0" onchange ="upfile.value=this.value" name="file["+num+"]">"+                  " <input type="button" name="Submit2" value="修改描述信息" class="button" onclick="changeContent("+num+")> ""+                  "<input type="button" name="Submit2" value="刪 除" class="button"></td></tr>";我有num個(gè)img標(biāo)簽，<img src="" id="img[0]" > <img src="" id="img[1]" ><img src="" id="img[2]" ><img src="" id="img[3]" >......然后我想在javascript中使用function  changeContent(var i){  var o = document.getElementById(""); var c = o.innerHTML;  o.innerHTML = "<input type='text' value='" + c + "'/>"}來(lái)引用第i個(gè)img，document.getElementById()改怎么寫(xiě)?用document.getElementById("img[i]");對(duì)嗎？