Loading Images Asynchronously Inside a GridView

1) Add a template field for gridview.

<asp:TemplateField>

<HeaderTemplate>Picture</HeaderTemplate>

<ItemTemplate>

<img border="1" src="images/cursor.jpg" onerror="this.src=images/error.jpg" onload="RetrievePicture(this,'<%# Eval("pic_id")%>');"/>

</ItemTemplate>

</asp:TemplateField>

2) Javascript function to call.

<script type="text/javascript" language="javascript">

function RetrievePicture(imgCtrl, picid)

        {

            imgCtrl.src = 'ShowImage.ashx?id=' + picid;

        }

</script>