function getCheckEntries()
{
    var checkaut = valButton(document.fw_upd_form.AutMan);
    if (checkaut=="Manual")
    {   
        var valueChk = "Check_Manual";
        document.getElementByName("value1").value = valueChk;
    }
    else if (checkaut=="Auto")
    {
        var valueChk = "Check_Auto";
        document.getElementByName("value1").value = valueChk;
    }
 }

<form name="fw_upd_form" id="fw_upd_form" method="post" action="index.htm" enctype="application/x-www-form-urlencoded" onSubmit="getCheckEntries()">

<input type="hidden" name="value1" />

<tr>
    <td nowrap="nowrap" style="text-align:center;width:50px">
        <input name="AutMan" value="Auto" type="radio" <%=(FwAutoUpgrade.getValue() == 1 ? "checked=\"checked\"" : "") %>/>
    </td>
    <td nowrap="nowrap" style="vertical-align:bottom;text-align:left">Automatic</td>
 </tr>
 <tr>
    <td nowrap="nowrap" style="text-align:center;width:50px">
        <input name="AutMan" value="Manual" type="radio" <%=(FwAutoUpgrade.getValue() == 0 ? "checked=\"checked\"" : "") %>/>
    </td>
    <td nowrap="nowrap" style="vertical-align:bottom;text-align:left">Manual</td>
 </tr>

#ifdef DLL_LIB_EXPORTS
	#define DLL_LIB_API __declspec(dllexport)
#else
	#define DLL_LIB_API __declspec(dllimport)
#endif

// Clase exportada de DLL_lib.dll
class DLL_LIB_API CDLL_lib 
{
  private:
    int a;
	int b;
  public:
	CDLL_lib(void);
	// TODO: agregar métodos aquí.
	double multiplica();
	int getA();
	int getB();
	void setA(int a);
	void setB(int b);
};

DLL_LIB_API int suma(void);

extern DLL_LIB_API int nDLL_lib;

DLL_LIB_API int fnDLL_lib(void);

#include "stdafx.h"
#include "DLL_lib.h"


#ifdef _MANAGED
#pragma managed(push, off)
#endif

BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
					 )
{
	switch (ul_reason_for_call)
	{
	case DLL_PROCESS_ATTACH:
	case DLL_THREAD_ATTACH:
	case DLL_THREAD_DETACH:
	case DLL_PROCESS_DETACH:
		break;
	}
    return TRUE;
}

#ifdef _MANAGED
#pragma managed(pop)
#endif

// Ejemplo de variable exportada
DLL_LIB_API int nDLL_lib=0;

// Ejemplo de función exportada.
DLL_LIB_API int fnDLL_lib(void)
{
	return 42;
}

DLL_LIB_API int suma(void)
{
	return 5+5;
}

// Constructor de clase exportada.
// Consultar DLL_lib.h para definir la clase
CDLL_lib::CDLL_lib()
{
	this->a = 0;
	this->b = 0;
}

int CDLL_lib::getA()
{
	return a;
}

int CDLL_lib::getB()
{
	return b;
}

void CDLL_lib::setA(int a)
{
	this->a = a;
}

void CDLL_lib::setB(int b)
{
	this->b = b;
}

double CDLL_lib::multiplica()
{
	return (double)a*b;
}

using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Runtime.InteropServices;


namespace app_usa_dll
{
    class Program
    {
        /// <summary>
        /// Punto de entrada principal para la aplicación.
        /// </summary>
        [STAThread]
        [DllImport(/*" ..\\..\\..\\debug\\*/"DLL_lib.dll")]
        public static extern int suma();
        [DllImport(/*" ..\\..\\..\\debug\\*/"DLL_lib.dll")]
        public static extern void setA(int a);
        [DllImport(/*" ..\\..\\..\\debug\\*/"DLL_lib.dll")]
        public static extern void setB(int b);
        [DllImport(/*" ..\\..\\..\\debug\\*/"DLL_lib.dll")]
        public static extern double multiplica();
        [DllImport(/*" ..\\..\\..\\debug\\*/"DLL_lib.dll")]
        public static extern int getA();
        [DllImport(/*" ..\\..\\..\\debug\\*/"DLL_lib.dll")]
        public static extern int getB();
        
        
        static void Main()
        {
            int a = 0;
            int b = 0;
            double c = 0;
            int res = 0;
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            //funciones de la dll
            try
            {
                /*a = setA(int.Parse(textBox3.Text));
                b = setB(int.Parse(textBox2.Text));
                c = multiplica();*/
                res = suma();
                setA(int.Parse("5"));
                a = getA();
                setB(int.Parse("6"));
                b = getB();
                c = multiplica();
                res = suma();
            }
            catch (DllNotFoundException exc)
            {
                Console.WriteLine(exc.ToString());
            }
            catch (EntryPointNotFoundException exc)
            {
                Console.WriteLine(exc.ToString());
            }
            Application.Run(new Form1(a, b, c, res));
        }
    }
}