Dynamically add guid src to iframe

[sirnose1]

Hi there. I am working on a single sign on solution that generate a guid. This guid will need to append to the address to complete the string. I dont believe it is working. Limited experience with iframes. I can generate the guid and save it to a lable control and then append there, howver, I dont think it is working. Is there something wrong with this code?

<iframe height="700px" id="iframeAssessments" runat="server" width="100%" src="

https://somewhere.com/cms/UCMMaster?sessionGUID='<%=lblSSOToFrame.Text

%>'">

</iframe>

Thanks in advance.