function init() {
  if (document.getElementById) {
	  
	document.getElementById("message").style.visibility= 'hidden';
  }
    if(window.XMLHttpRequest) {
    	try {
			objReq = new XMLHttpRequest();
        } 
         catch(e) {
			objReq = false;
        }
    // branch for IE/Windows ActiveX version
    } 
    else if(window.ActiveXObject) {
       	try {
        	objReq = new ActiveXObject("Msxml2.XMLHTTP");
      	} 
        catch(e) {
        	try {
          		objReq = new ActiveXObject("Microsoft.XMLHTTP");
        	} 
                catch(e) {
          		objReq = false;
                }
        }
    }
    
}

   /* for Mozilla */
   if (document.addEventListener) {
       document.addEventListener("DOMContentLoaded", init, false);
   }

   /* for Internet Explorer */
   /*@cc_on @*/
   /*@if (@_win32)
       document.write("<script defer src=ie_onload.js><"+"/script>");
   /*@end @*/

   /* for other browsers */
   window.onload = init;

function vselect(info) {
	
	if (objReq==null) 
	{
		return;
	}

	makeobj=document.forms[0].make;
	make=makeobj.options[makeobj.selectedIndex].value;
	modelobj=document.forms[0].model;
	model=modelobj.options[modelobj.selectedIndex].value;
	yearobj=document.forms[0].year;
	year=yearobj.options[yearobj.selectedIndex].value;
	sizeobj=document.forms[0].wsize;
	size=sizeobj.options[sizeobj.selectedIndex].value;

	maked=document.getElementById('makediv');
	modeld=document.getElementById('modeldiv');
	yeard=document.getElementById('yeardiv');
	sized=document.getElementById('sizediv');
	vinfod=document.getElementById("vinfo_button");

	var url="vselect.php";

	if (info=='make') {
		model='';
		year='';
		size='';
		modeld.innerHTML="<select name=\"model\" class=\"car_dropdown\" onchange=\"vselect('model')\"><option value=\"\"> Select Model\n</select>";
		yeard.innerHTML="<select name=\"year\" class=\"car_dropdown\" onchange=\"vselect('year')\"><option value=\"\"> Select Year\n</select>";
		sized.innerHTML="<select name=\"wsize\" class=\"car_dropdown\" onchange=\"vselect('size')\"><option value=\"\"> Select Size\n</select>";
		url=url+"?make="+make;
	}
	else if (info=='model') {
		year='';
		yeard.innerHTML="<select name=\"year\" class=\"car_dropdown\" onchange=\"vselect('year')\"><option value=\"\"> Select Year\n</select>";
		size='';
		sized.innerHTML="<select name=\"wsize\" class=\"car_dropdown\" onchange=\"vselect('size')\"><option value=\"\"> Select Size\n</select>";
		url=url+"?make="+make+"&model="+model;
	}
	else if (info=='year') {
		url=url+"?make="+make+"&model="+model+"&year="+year;
	}
	else if (info=='size') {
		url=url+"?make="+make+"&model="+model+"&year="+year+"&size="+size;
	}
	objReq.open("GET",url,true);
	objReq.onreadystatechange=writesel;
	objReq.send(null);
}

function writesel() {
	if (objReq.readyState==4) {
		if (make=='') {
			maked.innerHTML = objReq.responseText;
		}
		else if (model=='') {
			modeld.innerHTML = objReq.responseText;
		}
		else if (year=='') {
			yeard.innerHTML = objReq.responseText;
		}
		else if (size=='') {
			sized.innerHTML = objReq.responseText;
		}
		else {
			vinfod.innerHTML = objReq.responseText;
		}

	}
}