function changeMake(product_type)
    {
    	var model_selector = $('#model_selector')[0];
    	var make=$('#make_selector')[0].options[$('#make_selector')[0].selectedIndex].value;
    	if (make==0)
    	{
    		model_selector.disabled=true;
    		model_selector.style.color="#808080";
    	}
    	else
    	{
    		var url='mm_selector.php';
    		var pars='make='+make+'&product_type='+product_type;
    		var req = $.post(url, {make: make, product_type: product_type}, function(data){cb_changeMake(data);}, "json");
    	}
    }
    
    function cb_changeMake(data)
    {
    	var model_selector=$('#model_selector')[0];
    	if (data.length>0)
    	{
    		model_selector.options.length=0;
    		var opt,prev;
    		opt=document.createElement("option");
    		opt.value=0;
		opt.text="Select Model";
    		prev = model_selector.options[model_selector.options.length];
            try {
               model_selector.add(opt, prev);
            }
            catch (ex) {
               model_selector.add(opt, 0);
            }
    		for (var i=0; i<data.length; ++i)
    		{
    			opt=document.createElement("option");
			opt.value=data[i].categoryid;
    			opt.text=data[i].category;
    			prev = model_selector.options[model_selector.options.length];
                try {
                    model_selector.add(opt, prev);
                }
                catch (ex) {
                   model_selector.add(opt, i+1);
                }
    		}
    		model_selector.disabled=false;
    		model_selector.style.color="#111";
    		changeModel('Select Model');
    	}
	else
	{
		model_selector.disabled=true;
		model_selector.style.color="#808080";
	}
    }
    
    function changeModel(product_type)
    {
    	var year_selector = $('#year_selector')[0];
    	var model=$('#model_selector')[0].options[$('#model_selector')[0].selectedIndex].value;
    	if (model=='0')
    	{
    		year_selector.disabled=true;
    		year_selector.style.color="#808080";
    	}
    	else
    	{
    		var url='mm_selector.php';
		var req = $.post(url, {model: model, product_type: product_type}, function(data){cb_changeModel(data);}, "json");
    	}
    }
    
    function cb_changeModel(data)
    {
    	var year_selector=$('#year_selector')[0];
    	if (data.length>0)
    	{
    		year_selector.options.length=0;
    		var opt,prev;
    		opt=document.createElement("option");
    		opt.value='0';
		opt.text="Select Year";
    		prev = year_selector.options[year_selector.options.length];
            try {
               year_selector.add(opt, prev);
            }
            catch (ex) {
               year_selector.add(opt, 0);
            }
    		for (var i=0; i<data.length; ++i)
    		{
    			opt=document.createElement("option");
    			opt.value=data[i].categoryid;
			opt.text=data[i].category;
    			prev = year_selector.options[year_selector.options.length];
                try {
                    year_selector.add(opt, prev);
                }
                catch (ex) {
                   year_selector.add(opt, i+1);
                }
    		}
    		year_selector.disabled=false;
    		year_selector.style.color="#111";
    	}
	else
	{
		year_selector.disabled=true;
		year_selector.style.color="#808080";
	}
    }
    
    function goMakeModelYear(suffix)
    {
    	var make_selector=$('#make_selector')[0];
    	var model_selector=$('#model_selector')[0];
    	var year_selector=$('#year_selector')[0];
    	var make=make_selector.options[make_selector.selectedIndex].value;
    	var model=model_selector.options[model_selector.selectedIndex].value;
    	var year=year_selector.options[year_selector.selectedIndex].value;
    	if (!make_selector.disabled && !model_selector.disabled && 
!year_selector.disabled
    		&& make!='0' && model!='0' && year!='0')
    	{
    		document.location.href="/home.php?cat="+year;
    		return true;
    	}
	else
	{
		alert('Please select right options');
	    	return false;
	}
    }