hi Jeff
i know the usage of property ProgressBarBackgroundImage, what i need to change is green block, not the whole background,
i found green block defintion is below
"
<div style="position:absolute;font-size:1px;top:0px;left:0px;width:360px;height:40px;background-image: url(/abc/CuteWebUI_Uploader_Resource.axd?type=file&file=continuous.gif&_ver=634550129540000000);background-repeat: repeat-x;"></div>
"
but i can't find any file name like continuous.gif