I cant seem to make my code calculate here it is...

<title>JavaScript Forms



function compute()
{
two=2
var a=parseFloat(document.answer.area.value)
var b=(Math.PI)*a*a
var c=parseFloat(2)*parseFloat(num1)+parseFloat(D)
var d=parseFloat(2)*parseFloat(num2)
document.answer.area.value=b
document.answer.perimeter.value=c

}





Enter Length and width then click <br><br>
Length<br><br>
Width<br><br>
Area<br><br>
Perimeter<br>