Passing query string value as a static custom control property

Hi there, 
<cc2:ChecklistTableControl ID="cwChecklistControl" runat="server" ShowSaveButtons = "false" ReadOnly = "false" WorkItemGuid = '<%=request.querystring("workInstructionId")%>' />
I am trying to pass the query string value as above in the aove custom control - Please can someone suggest whether this is the right way of doing or is there any better way? Appreciate your help in advance. 
P.S. I know how to do this in code behind but trying to learn how to do it in the markup.  
Regards
Arun
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