이미지 미리보기

<script>
function previewImg(img,obj) {
    if (img.length == 0) return;

    idx = img.lastIndexOf("\\");
    filename = img.substring(idx+1);
    idx2 = filename.lastIndexOf(".");
    ext = filename.substring(idx2+1);
    ext2 = ext.toLowerCase();

    if ( ext2 == "jpg" || ext2 == "gif" || ext2 == "jpeg" || ext2 == "png" ) {
        obj.innerHTML = "<img src=\"file://" + img + "\" width=200>";
    }
}
</script>

<input type="file" name="file1" onfocus="previewImg(this.value,view1);">
<span id="view1"><img src="default img" alt="default img"></span>