Passing a client-side javascript variable to server code

Greetings,

I have a GridView that shows stock orders with custom "selecting" functionality (all the interaction is done on the client side, via global javascript variables).  When the user 'selects' a row in the GridView by clicking on a row, no server calls are made.  When a row is 'selected' the user has the option of hitting another button that Removes the order from the server's database.  I have a Web Service that takes the OrderID (a string) and deletes the order from the trading system.  I have the OrderID of the currently "selected" row stored in a global JavaScript variable, but I need to pass this to my Web Service in the ASP.NET event handler for my Button OnClick event.  How should I go about doing this?

 Thanks,

Rick
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