function count() {

var operate = document.getElementById('operate'),

num1 = document.getElementById('num1'),

num2 = document.getElementById('num1'),

result = document.getElementById('result');

var operation = {

add: function (num1, num2) {

result.value = + +num1 + +num2;

},

subtract: function (num1, num2) {

result.value = num1 - num2;

},

multiply: function (num1, num2) {

result.value = num1 * num2;

},

divide: function (num1, num2) {

result.value = num1 / num2;

}

};

switch (operate.value) {

case "+":

operation.add(num1.value, num2.value);

break;

case "-":

operation.subtract(num1.value, num2.value);

break;

case "*":

operation.multiply(num1.value, num2.value);

break;

case "/":

operation.divide(num1.value, num2.value);

break;

}

}