jsp上傳圖片實時顯示

jsp代碼

<div class="form-group" id="caseIma">
<label class="control-label">案例圖片</label>
<label class="btn btn-primary">選擇圖片
<input type="file" style="display: none" class="form-control" id="caseImage" name="caseImage"
onchange="viewImage(this)"/>
</label>
!--<p class="help-block">建議尺寸88*88</p>-->
</div>
<div id="localImag"><img id="preview" width=-1 height=-1 style="diplay:none" />
</div>

js代碼

//上傳圖片后預覽圖片
function viewImage(file){
            var preview = document.getElementById('preview');
            if(file.files && file.files[0]){
                //火狐下
                preview.style.display = "block";
                preview.style.width = "300px";
                preview.style.height = "120px";
                preview.src = window.URL.createObjectURL(file.files[0]);
            }else{
                //ie下，使用濾鏡
                file.select();
                var imgSrc = document.selection.createRange().text;
                var localImagId = document.getElementById("localImag"); 
                //必須設置初始大小 
                localImagId.style.width = "250px"; 
                localImagId.style.height = "200px"; 
                try{ 
                localImagId.style.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale)";
                locem("DXImageTransform.Microsoft.AlphaImageLoader").src = imgSrc; 
                }catch(e){ 
                alert("您上傳的圖片格式不正確，請重新選擇!"); 
                return false; 
                } 
                preview.style.display = 'none'; 
                document.selection.empty(); 
                } 
                return true; 
        }