Server Error in '/' Application.

Compilation Error

Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS0103: The name 'category_id' does not exist in the current context

Source Error:

Line 19: 
Line 20: 	templateBuilder.Append("<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"\">\r\n<html xmlns=\"\">\r\n<head>\r\n<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\" />\r\n");
Line 21: 	string fid = get_category_fid(channel,category_id);
Line 22: 
Line 23: 	string category_title = get_category_title(model.category_id,"Service");

Source File: d:\web\c_web\\wwwroot\aspx\en\esev_show.aspx    Line: 21

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1011