Strict Standards: Only variables should be passed by reference - php

Question

I'm quite new to php and I tested this code on my local server and it was working fine but when I uploaded it to webserver I started getting the following errors.
This is the Code :
"if($stmt=$mysqli->prepare("SELECT members.id, permissions.name FROM members,permissions WHERE username=? AND password=? AND members.type=permissions.id" )){
$username=$input["user"];
$password=$input["pass"];
$configsalt=$config["salt"];
$stmt->bind_param("ss",$username,md5($password.$configsalt));
$stmt->execute();
$stmt->bind_result($id,$type);
$stmt->fetch();"
The line 39 is "$stmt->bind_param("ss",$username,md5($password.$configsalt));"
Strict Standards: Only variables should be passed by reference in
/home/hotel132/public_html/bulbmg/index.php on line 39
Fatal error: Cannot redeclare is_admin() (previously declared in /home/hotel132/public_html/bulbmg/includes/config.php:22) in /home/hotel132/public_html/bulbmg/includes/config.php on line 28
I don't know why the second error is occuring!!!
'
.......
//Functions
function is_admin(){
if($_SESSION['type']=="admin"){
return true;
}
else{
return false;
}
} //line 28
?>'
Kidly help me out with this.

Answer 1

You should not use literals, try using variables.
The error:
Are you including or requiring file(s) more than one time? Try include_once/require_once
Otherwise check function_exists
EDIT:
Have you tried this?
if (!function_exists('is_admin')) {
function is_admin(){
if($_SESSION['type']=="admin")
return true;
else
return false;
}
}