I am using an html form that submits data to a MYSQL database. I need to add a button that will increase the number in the text box by one every time pressed. My code looks like this:

```
<label for="htop">Top: </label>
<input type="button" name="decrease" value="-" /><input type="text" name="htop" value="0" />
<input type="button" name="increase" value="+" />

```

What is the best way to do this?