I want a webpage that has something like this:

Welcome   

[textbox] [textbox] [Multiply!]   

Enter a value to multiply.

represented by this html code:

```js
window.onload = function begin() {
  document.getElementById("demo").innerHTML = "Welcome";
}

function multiply(var1, var2) {
  document.getElementById('multiply').innerHTML = var1 * var2
}
```

```html
<body onload="onload();">
  <p id='demo'> </p>

  <form>
    <input type='number' name=num1>
    <input type='number' name=num2>
    <button onclick=multiply(num1, num2)> Multiply! </button>
  </form>

  <p id='multiply'> Enter a value to multiply. </p>

</body>
```