$(document).ready(function() {
    load();
    $("#submit").click(function(){
	submitForm(); return false;
    })
    $("#reset").click(function(){
	load(); return false;
    })
});

function submitForm()
{
    if (($("#price").val() == 0) || !parseInt($("#price").val()))
    {
	alert("Please, enter the price");
	$("#price").focus();
    }
    else if (($("#i_rate").val() == 0) || !parseInt($("#i_rate").val()))
    {
	alert("Please, enter the interest rate");
	$("#i_rate").focus();
    }
    else if (($("#term").val() == 0) || !parseInt($("#term").val()))
    {
	alert("Please, enter the term");
	$("#term").focus();
    }
    else
    {
	calculate();
    }
}
function load()
{
    var href = window.location.href;
    var price = href.substring(href.lastIndexOf('?')+1, href.length);
    $("#calc").val('');
    $("#price").val(price);
    $("#downpay").val(0);
    $("#i_rate").val(0);
    $("#term").val(0);
}

function calculate()
{
    var principal = $("#price").val() - $("#downpay").val();
    var m_count = $("#term").val() *12;
    $("#principal").val(principal);
    $("#payments_count").val(m_count);
    var i_rate = $("#i_rate").val() / 1200;
    $("#monthly").val(Math.floor((principal*i_rate)/(1-Math.pow(1+i_rate,(-1*m_count)))*100)/100);
}