what must I replace with Visible attribute in c#?

Hey there

I need a small fixing. I am brand-new to C#. I wrote codes in code behind (C#) to access data to my gmail account.

I got the email from my gmail account - look at the problem data (bold):

Name: xxx
Surname: xxx
Email: xxxxx
Description:Card A6
Order:true // no data

It should be : Order: Images/order_names/faithcard.jpg

code behind:
msg += "<br>Description:" + description.Value; //correct
msg += "<br>Order:" + group1.Visible;// it is wrong. replace something with Visible??

I have put runat="server" in optgroup tag instead of select tag - it seems working because there is no displaying compile error.

markup:
<select name="order" multiple="multiple" size="12" style="width:330px;" id="dlist1" onchange="swapImage1()">
<optgroup label="Sow Seeds of Love" id="group1" runat="server">
<option selected="selected" value="Images/NoneImage.gif">None</option>
<option data-card="32.00" data-memo="62.00" data-tags1="1.80" data-tags4="8.50" data-key="30.00" data-fridge="40.00" data-flower_sachet="----" value="Images/Order_names/SowSeeds/Faith01_yellow.jpg">Faith</option>
</optgroup>

I am just asking what must I replace with Visible because it only displays "true" in email instead of full data such as Order:Images/order_names/faithcard.jpg?