cant get if statement to work correct

[Chrysanthus]

Hi im trying to get the if statment to work with checkhing for a user if he exist..

if not it shoulde print Ooops! - The nickname you chose don't exists! what have i misst!

<?php
$username = $_POST["username"];
$set = $_POST["set"];

function emailsyntax_is_valid($email) {
  $to_work_out = explode("@", $email);
  if (!isset($to_work_out[0])) return FALSE;
  if (!isset($to_work_out[1])) return FALSE;

  $pattern_local = '^([0-9a-z]*([-|_]?[0-9a-z]+)*)(([-|_]?)\.([-|_]?)[0-9a-z]*([-|_]?[0-9a-z]+)+)*([-|_]?)$';
  $pattern_domain = '^([0-9a-z]+([-]?[0-9a-z]+)*)(([-]?)\.([-]?)[0-9a-z]*([-]?[0-9a-z]+)+)*\.[a-z]{2,4}$';
  $match_local = eregi($pattern_local, $to_work_out[0]);
  $match_domain = eregi($pattern_domain, $to_work_out[1]);

  if ($match_local && $match_domain) {
    return TRUE;
  }
  return FALSE;
}




if ($set=="set") {

$username_control = 1;
$username2_control = 1;
$username3_control = 1;

$main_control = 1;

if($username == ""){
$empty_username = "Ooops! - You forgot to enter your username.";
$username_control = 0;
$main_control = 0;
}

elseif(strlen($username) < 4){
$empty_username = "Ooops! - Your username should be at least 4 letters long.";
$username2_control = 0;
$main_control = 0;
}

elseif(strlen($username) > 20){
$empty_username = "Ooops! - Your username can't be larger than 20 letters.";
$username3_control = 0;
$main_control = 0;
}

elseif($main_control = 1){
	$str = $username; 
	$str = strtolower($str);

	 require ('mysqlcondbrr.php'); 
     $result = mysql_query("SELECT username FROM reg_info where username=$str", $starta);
     while ($array = mysql_fetch_array($result)) {
    	if($str == $array["username"]) {
		$empty_username = "Ooops! - The nickname you chose don't exists!";
		$main_control2 = 1;
		break;
		mysql_close($starta);
		}

	}  

}
}

if($main_control2 != 1 && $main_control == 1) {

}

?>						
<?PHP

function info() {
}
print	"Please enter your usernamen in the blank field <br>
		below then after press get password button to <br> 
		get your password.<br>";

function validuser() 
{
print	"Welcome $_POST[username].in some seconds you <br>
		will recive a email with your password in it.<br>";

function invaliduser() {
}
print	"Sorry, incorrect username ( $_POST[username] ).<br>
		if not a member <a href=\"register.php\">click here to register.</a>"; 
}
?>

<br>
				        <form action="<?=$PHP_SELF?>" method="post" name="hej">
						<b>Your Username Here:</b><br><br>
						<input type="text" name="username" size="15" class="inputSidebar" value="<?php

					if($username_control != 0){ echo $_POST['username'];}

					elseif(username2_control !=0){ echo $_POST['username'];} 

					elseif(username3_control !=0){ echo $_POST['username'];}

					else{ echo ''; }  ?>"> 

					<?php echo $empty_username; ?> &nbsp &nbsp

					<input class="button" type="submit" name="submit" value="Get password">

					<?php echo $_POST['username']; ?>

					<input type="hidden" name="set" value="set">

				</form>

[YappyDog]

Not sure if this will solve your problem or not, but there are two problems that I see. Your elseif line needs a second equal sign (==) to be the correct syntax

elseif($main_control = 1){

And, this if statement doesn't do anything...........

if($main_control2 != 1 && $main_control == 1) {

}

[Chrysanthus]

Nopp that dident work...

[YappyDog]

Try putting single quotes around your username variable in the sql statement and converting the username in the table to lowercase as well.

$result = mysql_query("SELECT lower(username) FROM reg_info where username='$str' ", $starta);