Bueno, por fin! Tomando tus códigos y modificándolo para lo que lo necesitaba lo logré! Estoy muy agradecido, acá le dejo el siguiente aporte:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Documento sin título</title>
<script>
var valor1 = 0;
var valor2 = 0;
function sumar(radio) {
* * var valor = parseInt(radio.value);
* * if (radio.name == "RadioGroup1")
* * * * valor1 = valor;
* * else* *
* * * * valor2 = valor;
* * document.getElementById("resultado").value = valor1 + valor2;
}
</script>
*
</head>
*
<body>
<form id="form1" name="form1" method="post" action="">
* <table width="600">
* * <tr>
* * * <td><p>
* * * * <label>
* * * * * <input type="radio" name="RadioGroup1" value="1" onclick="sumar(this);" id="RadioGroup1_0" />
* * * * * Opción</label>
* * * * <br />
* * * * <label>
* * * * * <input type="radio" name="RadioGroup1" value="2" onclick="sumar(this);" id="RadioGroup1_1" />
* * * * * Opción</label>
* * * * <br />
* * * * <label>
* * * * * <input type="radio" name="RadioGroup1" value="3" onclick="sumar(this);" id="RadioGroup1_2" />
* * * * * Opción</label>
* * * * <br />
* * * * <label>
* * * * * <input type="radio" name="RadioGroup1" value="4" onclick="sumar(this);" id="RadioGroup1_3" />
* * * * * Opción</label>
* * * * <br />
* * * * <label>
* * * * * <input type="radio" name="RadioGroup1" value="5" onclick="sumar(this);" id="RadioGroup1_4" />
* * * * * Opción</label>
* * * * <br />
* * * </p></td>
* * * <td><p>
* * * * <label>
* * * * * <input type="radio" name="RadioGroup2" value="1" onclick="sumar(this);" id="RadioGroup2_0" />
* * * * * Opción</label>
* * * * <br />
* * * * <label>
* * * * * <input type="radio" name="RadioGroup2" value="2" onclick="sumar(this);" id="RadioGroup2_1" />
* * * * * Opción</label>
* * * * <br />
* * * * <label>
* * * * * <input type="radio" name="RadioGroup2" value="3" onclick="sumar(this);" id="RadioGroup2_2" />
* * * * * Opción</label>
* * * * <br />
* * * * <label>
* * * * * <input type="radio" name="RadioGroup2" value="4" onclick="sumar(this);" id="RadioGroup2_3" />
* * * * * Opción</label>
* * * * <br />
* * * * <label>
* * * * * <input type="radio" name="RadioGroup2" value="5" onclick="sumar(this);" id="RadioGroup2_4" />
* * * * * Opción</label>
* * * * <br />
* * * </p></td>
* * </tr>
* * <tr>
* * * <td colspan="2"><input type="text" name="resultado" id="resultado" disabled="disabled" value="0" /></td>
* * </tr>
* </table>
</form>
</body>
</html>