rh_calc = {
        
    calculateHeatPumpSizing: function()
    {
        
        // Required elements
        var room_area = document.getElementById('room_area');
        var ceiling_height = document.getElementById('ceiling_height');
        var location = document.getElementById('location');
        var insulation_level = document.getElementById('insulation_level');
        var calc1_result_container = document.getElementById('calc1_result_container');
        var calc1_result_kw = document.getElementById('calc1_result_kw');
        
        if(room_area && ceiling_height && location && insulation_level && calc1_result_container && calc1_result_kw){
            
            // Get values
            room_area = room_area.value;
            ceiling_height = ceiling_height.value;
            location = location.options[location.selectedIndex].value;
            insulation_level = insulation_level.options[insulation_level.selectedIndex].value;
            
            // Check if we have valid entries
            var error = '';
            if(room_area == '' || room_area * 1 != room_area){
                error += "- enter a number for the room area.\n";
            }
            if(ceiling_height == '' || ceiling_height * 1 != ceiling_height){
                error += "- enter a number for the ceiling height.\n";
            }
            if(location != 'ni' && location != 'si'){
                error += "- choose a location.\n";
            }
            if(insulation_level != 'well' && insulation_level != 'poorly'){
                error += "- choose your house insulation level.\n";
            }
            
            // Errors in the form?
            if(error != ''){
                error = "We can't calculate until you:\n\n" + error + "\nThank you!";
                alert(error);
                return;
            }
            
            // Get location vs. insulation number
            var combined_number;
            if(insulation_level == 'well' && location == 'ni'){
                combined_number = 55;
            } else if (insulation_level == 'well' && location == 'si') {
                combined_number = 60;
            } else if (insulation_level == 'poorly' && location == 'si'){
                combined_number = 75;
            } else {
                combined_number = 65;
            }
            
            // Let's calculate...
            var calc_result = (combined_number * room_area * ceiling_height)/1000;
            var rounded_calc_result = Math.round(calc_result*10)/10;
            
            // Enter value
            calc1_result_kw.innerHTML = rounded_calc_result;
            
            // Show container
            showElement("calc1_result_container");
            
            // Show result message
            showElement('calc1_message');
            setTimeout('hideElement("calc1_message");',5000);
            
        }
    
    },
    
    calculateRadiantHeatSizing: function()
    {
        
        // Required elements
        var underfloor_heating = document.getElementById('underfloor_heating');
        var small_rooms = document.getElementById('small_rooms');
        var medium_rooms = document.getElementById('medium_rooms');
        var large_rooms = document.getElementById('large_rooms');
        var calc2_result_container = document.getElementById('calc2_result_container');
        var calc2_result_radiators = document.getElementById('calc2_result_radiators');
        var calc2_result_underfloor = document.getElementById('calc2_result_underfloor');
        var calc2_result_total = document.getElementById('calc2_result_total');
        
        if(underfloor_heating && small_rooms && medium_rooms && large_rooms && calc2_result_container && calc2_result_radiators && calc2_result_underfloor && calc2_result_total){
            
            // Get values
            underfloor_heating = underfloor_heating.value;
            small_rooms = small_rooms.options[small_rooms.selectedIndex].value;
            medium_rooms = medium_rooms.options[medium_rooms.selectedIndex].value;
            large_rooms = large_rooms.options[large_rooms.selectedIndex].value;
            
            // Check if we have valid entries
            var error = '';
            if(underfloor_heating == '' || underfloor_heating * 1 != underfloor_heating){
                error += "- enter a number for the area of underfloor heating.\n";
            }
            if(small_rooms == 0 && medium_rooms == 0 && large_rooms == 0){
                error += "- choose at least one room size.\n";
            }
            
            // Errors in the form?
            if(error != ''){
                error = "We can't calculate until you:\n\n" + error + "\nThank you!";
                alert(error);
                return;
            }
            
            // Let's calculate...
            var heat_load_radiators = (small_rooms*1.5) + (medium_rooms*2) + (large_rooms*3);
            var heat_load_underfloor = ((underfloor_heating*75)/1000);
            var heat_load_total = heat_load_radiators + heat_load_underfloor;
            
            // Enter values
            calc2_result_radiators.innerHTML = heat_load_radiators;
            calc2_result_underfloor.innerHTML = heat_load_underfloor;
            calc2_result_total.innerHTML = heat_load_total;
            
            // Show container
            showElement("calc2_result_container");
            
            // Show result message
            showElement('calc2_message');
            setTimeout('hideElement("calc2_message");',5000);
            
        }
        
    }
        
}