i have combobox code like this
<form action="plot.php" method="POST">
<select name="variabel">
<option value="no2">NO2</option>
<option value="so2">SO2</option>
<option value="ozone">ozone</option>
<option value="aerosol">aerosol</option>
</select>
<input type="submit" value="plot" style="width:500px;height:48px">
and in file named "plot.php" like this
<?php
$variabel = $_POST['variabel'];
if ($variabel = "no2") {
header("location:maps_no2.php");
} else if ($variabel = "so2") {
header("location:maps_so2.php");
} else if ($variabel = "ozone") {
header("location:maps_ozone.php");
} else {
header("location:maps_aerosol.php");
}
?>
all i want is when i pick one of the item in my combobox, it will be the parameter for the other page to open after i click "plot" button. for the example, when i pick NO2, maps_no2.php will show. when i try that code above, it just work on the first condition, although i pick so2. how can i solve this? anyone?? please.