I'm stuck with a php code:

Code:
if ($currency="EUR") {
    $curr = "€";
} elseif ($currency="GBP") {
    $curr = "£";
} else {
    $curr = "$";
}
echo $curr;
The $currency is defined, but $curr is always showing EUR. I'm sure there is only a small thing that I'm missing, but I'm new with php and can't solve this problem.

Some help would be appreciated!
Thank you!