newbie: problem understandig this code

[Jeff]

hey

asp.net 2.0

I'm reading the asp.net cookbook and there I found a example I have some
problem understanding:
// set the source to the page that generates the thumbnail image
img.Src = CH12ThumbnailFromDatabaseCS.PAGE_NAME + "?" +
CH12ThumbnailFromDatabaseCS.QS_IMAGE_ID + "=" +
(((DbDataRecord)(e.Item.DataItem))["BookImageID"]).ToString();

More specific I'm wondering if "CH12ThumbnailFromDatabaseCS.PAGE_NAME" is
representing a .aspx file or a class. My gut feeling is that it is
referencing a class (which represent the code behind of a webpage)....

I'm trying to implement this code myself (this is just a part of my code):
protected void rptInbox_ItemDataBound(object sender, RepeaterItemEventArgs
e)
{
System.Web.UI.HtmlControls.HtmlImage img = null;
if ((e.Item.ItemType == ListItemType.Item) || (e.Item.ItemType ==
ListItemType.AlternatingItem)) {
img = (System.Web.UI.HtmlControls.HtmlImage)e.Item.FindControl("Photo");
img.Src = webForms_Profile_Thumbnail


You see that I'm not finished with the "img.Src =
webForms_Profile_Thumbnail" line... but here my problem starts. that line
cannot be correct because when I add "." -> "img.Src =
"webForms_Profile_Thumbnail." no type ahead box appear... so I guess my
syntax is wrong... When I remove the "img.Src = webForms_Profile_Thumbnail"
my code compiles...

So what is the CH12ThumbnailFromDatabaseCS?

(I guess if I understand what "CH12ThumbnailFromDatabaseCS" is, then I
easier can implement my own version of it)

Jeff