javascript display

[Vani Sweety]

hello everyone
i really need help for my project
i have a database for car
i am using javascript and php to access the database
upon click a list is displayed and i have use javascipt onclick to implement this. Now
i have to make a search according to its id to go fetch the value which has this id and display the available car version

after displaying the list of car version which is a dynamic list
obtain from the database, the user has to be able to click
the version listed so that all the details according to this version are displayed.

Can anyone suggest me how to proceed with this please.

This is a piece of code  so far
Javascript

function a1()
{
	document.getElementById("malfaromeo").style.display = "inline";
	document.getElementById("maudi").style.display = "none";
	document.getElementById("maustin").style.display = "none";
	document.getElementById("mbmw").style.display = "none";
	document.getElementById("mchevrolet").style.display = "none";
	document.getElementById("mcitroen").style.display = "none";
	document.getElementById("mcooper").style.display = "none";
	document.getElementById("mdaewoo").style.display = "none";
	document.getElementById("mdaihatsu").style.display = "none";
	document.getElementById("mds").style.display = "none";
	document.getElementById("mfiat").style.display = "none";
	document.getElementById("mford").style.display = "none";
	document.getElementById("mgmw").style.display = "none";
	document.getElementById("mhino").style.display = "none";
	document.getElementById("mhonda").style.display = "none";
	document.getElementById("mhynudai").style.display = "none";
	document.getElementById("misuzu").style.display = "none";
	document.getElementById("mjaguar").style.display = "none";
	document.getElementById("mjmc").style.display = "none";
	document.getElementById("mkia").style.display = "none";
	document.getElementById("mlandrover").style.display = "none";
	document.getElementById("mmahindra").style.display = "none";
	document.getElementById("mmazda").style.display = "none";
	document.getElementById("mmercedes").style.display = "none";
	document.getElementById("mmercedesbenz").style.display = "none";
	document.getElementById("mmitsubishi").style.display = "none";
	document.getElementById("mmini").style.display = "none";
	document.getElementById("mnissan").style.display = "none";
	document.getElementById("mopel").style.display = "none";
	document.getElementById("mperodua").style.display = "none";
	document.getElementById("mpeugeot").style.display = "none";
	document.getElementById("mporsche").style.display = "none";
	document.getElementById("mproton").style.display = "none";
	document.getElementById("mrenault").style.display = "none";
	document.getElementById("mrangerover").style.display = "none";
	document.getElementById("msubaru").style.display = "none";
	document.getElementById("msuzuki").style.display = "none";
	document.getElementById("mtoyota").style.display = "none";
	document.getElementById("mvolkswagen").style.display = "none";
	
}

function car(elId) {
	var hr;
    ab = document.getElementById(elId).id;
	if (window.ActiveXObject)
	{// code for IE6, IE5 
		try{
			hr = new ActiveXObject("Microsoft.XMLHTTP");
		}catch(e){
			hr = false;
		}
	}
	else
	{// code for IE7+, Firefox, Chrome, Opera, Safari
		try{
			hr = new XMLHttpRequest();
		} catch(e){
			hr = false;
		}
	}
	hr.open("POST", "model1.php", true);
	hr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
	hr.onreadystatechange = function() 
	{
		if(hr.readyState == 4 && hr.status == 200) 
		{
			alert(hr.responseText);
		}
	}
	v = "sendab="+ab;
	hr.send(v);
	}

this is my php code

<?php 
//load database connection
    $host = "localhost";
    $user = "root";
    $password = "vani";
    $database_name = "food";
    $port = "3306";

$Rname = $_POST['sendab'];
	
// Create connection
$conn = new mysqli($host, $user, $password, $database_name, $port);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

$sql = "SELECT name FROM start WHERE name='$Rname'";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {
        echo $row["name"];
    }
} else {
    echo "0 results";
}

$conn->close();
?>

and here is where it is found in my html

			<li id="click" onclick="a36()">Subaru</li>
				<li id="click" onclick="a37()">Suzuki</li>
				<li id="click" onclick="a38()">Toyota</li>
				<li id="click" onclick="a39()">Volkswagen</li>
				</ul>

		</div>
		<div id= "carmodel">
		
				<ul id="malfaromeo" hidden>
				</br>
				</br>
				</br>
				</br>
					<li id="alfaromeo4c" onclick="car(this.id)">4C</li>
					<li id="alfaromeoGiulietta" onclick="car(this.id)">Giulietta</li>
				</ul>
				<ul id="maudi" hidden>
				</br>
				</br>
				</br>
				</br>
					<li id="audiA1" onclick="car(this.id)">A1</li>
					<li id="audiA3" onclick="car(this.id)">A3</li>
					<li id="audiA4" onclick="car(this.id)">A4</li>
					<li id="audiA5" onclick="car(this.id)">A5</li>
					<li id="audiA6" onclick="car(this.id)">A6</li>
					<li id="audiA7" onclick="car(this.id))">A7</li>