Hi,

There is no property. You have 2 options:

1. remove InsertImage from RightClickMenu (line similar to)
<ighedit:HtmlBoxMenuItem runat="server" Act="InsertImage"></ighedit:HtmlBoxMenuItem>

2. process ClientSideEvents.BeforeAction and cancel action which happens on that particular event. Below is example to implement.

<script type="text/javascript">
function WebHtmlEditor1_BeforeAction(oEditor, actID, oEvent, p4, p5, p6, p7, p8, act)
{
 if(actID != 'RightClick' || act != 'pop') return;
 // next block is optional
 if(p6)
 {
  var src = p6.srcElement;
  if(!src)
    src = src.target;
  if(src && src.nodeName != 'IMG')
    return;
 }
 oEvent.cancel = true;
}
</script>