PHP - Tengo un problimita simple!!!

<form name = "busqueda" action = "buscar.php" method ="post">

	<input type = "text" name ="consulta"></input>

	<input type="submit" name="busca" value="Enviar"></input>

</form>

<?php

$busqueda = $_POST['busqueda'];

$buscar = $_POST ['busca'];

	if (isset ($busca)){

		$conexion = mysql_connect ("localhost","root","1234") or die (mysql_error());

		$bd = mysql_select_db ("alquiler",$conexion) or die (mysql_error());

		$consulta = mysql_query ("SELECT  * FROM  vehiculos WHERE CODIGO LIKE 'consulta'");

		echo "<table border='1'>";

		while ($dato = mysql_fetch_assoc ($consulta)){

		echo '<tr>

		        <td width="226">'.$dato ['EMPRESA'].' </td>

			 </tr>';

			 }

			}

 ?>

$consulta = mysql_query ("SELECT  * FROM  vehiculos WHERE CODIGO LIKE '%".$_POST["consulta"]."%'");