function request(){
    
    var ajaxRequest;  // The variable that makes Ajax possible!
	



	try{
		// Opera 8.0+, Firefox, Safari
		ajaxRequest = new XMLHttpRequest();
	} catch (e){
		// Internet Explorer Browsers
		try{
			ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try{
				ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e){
				// Something went wrong
				alert("Your browser broke!");
				return false;
			}
		}
	}
        return ajaxRequest;
}


function car_type_onchange(type){
	var selectedindex=document.getElementById('car_type').selectedIndex;
	 var cartype=document.getElementById('car_type')[selectedindex].value;
	 
        //alert(type);
	var request_object_year=request();
        var request_object_mileage=request();
	
	var request_object_year_records=request();
        // Create a function that will receive data sent from the server
        
	request_object_year.onreadystatechange = function(){
		if(request_object_year.readyState == 4){
			document.getElementById('div_car_year').innerHTML = request_object_year.responseText;
		}
	}
	
	
	request_object_mileage.onreadystatechange = function(){
		if(request_object_mileage.readyState == 4){
			document.getElementById('div_car_mileage').innerHTML = request_object_mileage.responseText;
		}
	}
	
	
	request_object_year_records.onreadystatechange = function(){
		
		if(request_object_year_records.readyState==1){
			document.getElementById('car_list').innerHTML = '<div align=center><img src="/img/ajax-loader.gif" align=center></div>';
		}
		
		if(request_object_year_records.readyState == 4){
			document.getElementById('car_list').innerHTML = request_object_year_records.responseText;
		}
	}
	
	
	
	
	request_object_year.open("GET", "/inventory.php?type=type&option=year&value="+type, true);
        request_object_mileage.open("GET", "/inventory.php?type=type&option=mileage&value="+type+"&cartype="+cartype, true);
	request_object_year_records.open("GET", "/inventory.php?type=type&option=records&value="+type, true);
        //request_object_year.open("GET", "serverTime.php", true);
	request_object_year.send(null);
	request_object_mileage.send(null);
	request_object_year_records.send(null);
}




function car_year_onchange(year) {
         var selectedindex=document.getElementById('car_type').selectedIndex;
	 var cartype=document.getElementById('car_type')[selectedindex].value;
	
	//var request_object_type=request();
       
        var request_object_mileage=request();
	var request_object_year_records=request();
	// Create a function that will receive data sent from the server
       
	
        request_object_mileage.onreadystatechange = function(){
			
		if(request_object_mileage.readyState == 4){
			document.getElementById('div_car_mileage').innerHTML = request_object_mileage.responseText;
		}
	}
              
	 request_object_year_records.onreadystatechange = function(){
		 if(request_object_year_records.readyState==1){
			document.getElementById('car_list').innerHTML = '<div align=center><img src="/img/ajax-loader.gif" align=center></div>';
		}
		
		 
		 
		if(request_object_year_records.readyState == 4){
			document.getElementById('car_list').innerHTML = request_object_year_records.responseText;
		}
	}     
        
        request_object_mileage.open("GET", "/inventory.php?type=year&option=mileage&value="+year+"&cartype="+cartype, true);
	request_object_year_records.open("GET", "/inventory.php?type=year&option=record&value="+year+"&cartype="+cartype, true);
      //  request_object_type.open("GET", "serverTime.php", true);
	request_object_year_records.send(null);
	request_object_mileage.send(null); 
}


function car_mileage_onchange(miles){
      /* alert(miles);*/
	 var request_object_year_records=request();
        var selectedindex=document.getElementById('car_type').selectedIndex;
	var cartype=document.getElementById('car_type')[selectedindex].value;
	
	var selectedindexyear=document.getElementById('car_year').selectedIndex;
	var year2=document.getElementById('car_year')[selectedindexyear].value;
	/*alert(cartype);
	alert(year2);*/
	request_object_year_records.onreadystatechange = function(){
		
			if(request_object_year_records.readyState==1){
			document.getElementById('car_list').innerHTML = '<div align=center><img src="/img/ajax-loader.gif" align=center></div>';
		}
		
		
		if(request_object_year_records.readyState == 4){
			document.getElementById('car_list').innerHTML = request_object_year_records.responseText;
		}
	}


       
	//alert("http://localhost/gn/inventory.php?type=mileage&option=record&value="+miles+"year="+year2+"&cartype="+cartype);
	request_object_year_records.open("GET","/inventory.php?type=mileage&option=record&value="+miles+"&year="+year2+"&cartype="+cartype, true);
	request_object_year_records.send(null);
	
}