asp.net - assign a double value from the model to a property of a control -

I have a very difficult problem:

In the model, I have this property:

  Double Conversion Rate;   
 I would like to specify that value for a control property:  
    
 This works when I try hard to get coded, but when I try it like this:  
  & lt ; StoreControl: StoreUI ID = "StoreUI1" Runat = "server" conversion line = '& lt;% (double) model. Conversion rate% & gt; ' & Gt;   
 Then I found this error:  
  Can not create any type 'System.Double' representing its string.   
 How can I solve this problem?   
 
 
 Try this instead:  
  '< : (Double) Model. Conversion rate% & gt; '   
 Or alternatively  
  '  
 Hope this will help!