how to get values in form field
i have a template. this is my template
<form id="cal" method="get">
<span>Number1</span>
<input type="text" id="number1" name="number1"><br/>
<span>Number2</span>
<input type="text" id="number2" name="number2"><br/>
<input tye"text" id="result">
<input type="submit" value="calculated">
</form>
how to get value number1 and number2, and calculate number1 and number2