PHP Help: "IF" statments won't work

Website Building
#1

I have no blazen idea why it won’t work:

if($isloggedin = "yes"){

$us = $_GET["us"];
$us = secure($us);
$content = $content.$us."<br><br>";

if($us = "PG"){
$query = "SELECT * FROM ".$prefix."users WHERE username = '$loggedinname'";

$result = @mysql_query($query);

$power=@mysql_result($result,$i,"power");
$cash=@mysql_result($result,$i,"cash");
if($cash>20000 or $cash = 20000){
$powers = $power + 30;
$cashs = $cash - 20000;
$query = "UPDATE ".$prefix."users SET power='".$powers."' WHERE username='".$loggedinname."'"; 

mysql_query($query);
$query = "UPDATE ".$prefix."users SET cash='".$cashs."' WHERE username='".$loggedinname."'"; 

mysql_query($query);
$title = "New Upgrade!";
$content = $content."<br>The Power Generator has been upgraded.";
}
else{
$title = "Not Enough Resources!";
$content = $content."Sorry! You don't have enough resources! Please wait another billion seconds before buying this again. (Cost: 20000)";
}
}
else{
$content = $content."No such upgrade exists.";
}

}

It gives no error messages, practically skips the IFs and goes right on through.

#2

<?php
if ($foo == 3) bar();
?>

#3

Lol, thanks, never realized I could have made such a mistake. o.O