check

<?php
session_start();
$data= $_POST['data'];
$servername = "localhost";
$username = "root";
$password = "";
$dbname="chat";
$dbname2="mydatabase";
$dbcon = @mysqli_connect($servername, $username, $password, $dbname);
$dbconn=@mysqli_connect($servername, $username, $password, $dbname2);
if(!$dbconn){die("connection failed");}
if (!$dbcon) {
    die("Connection failed: " . mysqli_connect_error());
}
if(!$dbconn){die("connection failed");}
$grp=$_SESSION['grptable'];
$grpname=$_SESSION['grpname'];
$checkq="SELECT * FROM `chat`.`$grpname` WHERE usersname='$data'";
$resq=mysqli_query($dbconn,$checkq);
$userq=mysqli_fetch_array($resq);
if(!$userq){
$sql="SELECT * FROM `mydatabase`.`users` WHERE usersname='$data'";
$res=mysqli_query($dbcon,$sql);
$result=mysqli_fetch_array($res);
if($result){
$sqli="INSERT INTO `chat`.`$grpname` (`id`,`usersname`,`adminstatus`) VALUES ('NULL','$data','0')";
$resi=mysqli_query($dbconn,$sqli);
if($resi){
	$query="SELECT id FROM `chat`.`$grpname` WHERE usersname='$data'";
	$resquery=mysqli_query($dbconn,$query);
	$row=mysqli_fetch_array($resquery);
	$id=$row['id'];
	if($id==1){echo "admin";
	$update="UPDATE `chat`.`$grpname` SET `adminstatus`='1'";
	$resup=mysqli_query($dbconn,$update);
	}
	else{
echo "true";}}
}
else{echo "false";}}
else{die("You have already taken".$data);} 
?>