/* Using prototype.js event handlers for coverage calculator */
/* See the Prototype web site: http://www.prototypejs.org/   */

Event.observe(window, 'load', function()
{
    if ($('calculatorBottomBar') != undefined)
    {
        $('calculatorBottomBarContainer').hide();    

        Event.observe('calculateButton', 'click', function()
        {
            calculateCoverage();
        });
    }
});

function calculateCoverage()
{
    var message  = "You need about 1 gallon.";
    var areaSqFt = $('areaSquareFeet').value;
    var coverage = $('coveragePerGallon').value
    var gallons  = Math.round(areaSqFt / coverage);

    if (gallons > 1)
    {
        message = "You need about " + gallons + " gallons.";
    }

    //----- Show calculation
    $('calculatorBottomBar').innerHTML = message;
    Effect.Appear($('calculatorBottomBarContainer'));

    //----- For google tracking
    pageTracker._trackPageview('calculate-coverage.html');
}