Get email id on another page - php

Question

After submit in signup page my signUp page redirects to info.php where I want to collect additional info of user using email id he gives on signup page but when I tried to get the email id of user through sessions, session return empty value.
THIS IS MY SIGNUP CODE
<?php
session_start();
if(isset($_POST['submit'])){
$name= $_POST['_user'];
$email = $_POST['_email'];
$pass = $_POST['_password'];
//Insert Data
$sql = "INSERT INTO signup(name,email,password)
VALUES('$name','$email','$pass')";
//Data Validation
if(mysqli_query($conn,$sql)){
echo "<script>alert('SignUp Successfull')</script>";
$_SESSION['user_email'] = $email;
header('Location: info.php');
}
else{
echo "<script>window.alert('You are already a user.')</script>";
}
}
mysqli_close($conn);
?>
AND THIS MY INFO.PHP CODE
<?php
session_start();
if(isset($_POST['_submit'])){
if(empty($_POST['_address']) || empty($_POST['_country']) || empty($_POST['_number']) || empty($_POST['_cnic']) || empty($_POST['_passport'])){
echo "<script>window.alert('All fields are required')</script>";
}
else{
$address = $_POST['_address'];
$country = $_POST['_country'];
$number = $_POST['_number'];
$cnic = $_POST['_cnic'];
$passport = $_POST['_passport'];
$email=$_SESSION['user_email'];
$query = "INSERT INTO info(email,address,country,mobile,cnic,passport)
VALUES('$email','$address','$country','$number','$cnic','$passport')";
if(mysqli_query($conn,$query)){
header('Location: ../index.php');
}
else{
echo "<script>window.alert('Error While Entering the data!.')</script>";
}
}
}
mysqli_close($conn);
?>
In addition I use this global session variable for login page and it works fine.
UPDATE
SIGNUP HTML CODE
<div class="outside">
<form class="form-horizontal" role="form" method="post">
<div class="form-group">
<label class="control-label col-sm-3 glyphicon glyphicon-user" for="name"></label>
<div class="control-label col-sm-8">
<input type="text" name="_user" class="form-control" id="name" placeholder="Full Name">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-3" for="email">
<img class="glyphicon1" src="../assests/at-sign.png">
</label>
<div class="control-label col-sm-8">
<input type="email" name="_email" class="form-control" id="email" placeholder="Enter Email">
</div>
</div>
<div class="form-group">
<label class="control-label col-sm-3 glyphicon glyphicon-lock" for="password"></label>
<div class="control-label col-sm-8">
<input type="password" name="_password" class="form-control" id="password" placeholder="Enter Password">
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-3 col-sm-3">
<button name="submit" id="submit" value="Upload" type="submit" class="btn btn-default">Confirm SignUp</button>
</div>
</div>
<p>Already a User? LogIn</p>
</form>
</div>

Answer 1

Use this for Returns the auto generated id used in the last query
mysqli_insert_id($link)