Sorry for my beginner question but I am having some trouble getting this to work. I am trying to create a simple I=PRT calculator so it can calculate interest. But when you run it it adds the digits. Ex. 5+100=5100 instead of 105. Give it a try. My code is bellow.[CODE]

// JavaScript Document

alert("This is a simple calculator which will allow you to calculate the interest on a principle.");

var principle = prompt("What is the amount you would like to calculate interest for?");

var rate = prompt("What is the interest rate. eg. For 3.9% write 3.9");

var term = prompt("How long in the period under calculation going to be? eg. For 1 year write 1");

var interest = principle*(rate/100)*term;

var result = principle + interest;

var a = "This means the interest is going to be $";

var b = " And the total to be paid is $";

var c = a + interest + b + result;

alert(c);

[CODE]

Thanks in advance.