Can I use webcontrol to render a picture like that?

Hi, all,
I am using a webcontrol to render some charts into a page. I want to do something like this:
<page..>
<asp.textbox id.......>

<WebControlChart ID="StockPrice", xxxxx />
<WebControlChartIndicator ID="MA50", xxxxx/>

</page>
I only want the WebControlChart render as a picture, WebControlChartIndicator render as another picture. In the page, I will feed some data into these two controls. 
But now looks like, as soon as I changed the Response.ContentType to a picture in WebControlChart, the whole page will become a picture, and it will show only WebControlChart alone as the whole page. 
 I am wondering how should I achive this? I don't want the whole page only show one picture or chart.

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