How to consume the web service in window phone 7 application?

I am developing window phone 7 application. I am new to window phone 7 application. I am developing asp.net web service application in .net framework 3.5 for my wp7 application. I have written some function in this web service. Now I am trying to consume this web service by right clicking on the project name & selecting the 'Add Service Reference' then I clicked on the 'Advance' button. After clicking on the advance button I can see that the 'Add Web Reference' button is disabled. I am not able to enable it. Can you please tell me why this is happening ? Can we consume the asp.net web service application of .net framework 3.5 in wp7 application ? Or we can consume only WCF application of .net framework 4.0 in window phone 7 application ? If we can consume the asp.net web service开发者_JAVA百科 application of .net framework 3.5 then can you please tell me how to consume the asp.net web service application of .net framework 3.5?

You can add a service reference to an ASP.Net ASMX service. Just enter the url in the add service reference box. Silverlight does not support the old Web Reference proxies.

Try to do that as described here and here.