Q:

SQL, PHP: when submit plus 1 in table_field specified from dropdown

UPDATED (*the code is working and I updated the full code  :)   *) 
UPDATED (**edit the suggestions still dont work :)   **) 
Hi guys I have been looking around in many of the post in here regarding using php to plus 1 in a table_field specifed by a dropdown on the php page. I am very new to this so I just tried some things out to see if I could get it to work but for me this is not easy :)
So here we go.
as you can see in the code there is a drow down that fetch data from a member table. In this table there is a field "isMcount" when a person have chosen a member from the drop down and then press submit I need it to +1 in the "isMcount" column for that specified member which is active in the drop down
Hope you will help.
this is the table setup:
isMcount    Type=int(100)           Null=No Default=(as defiend)=1  
<?php 

require('includes/config.php'); ?>

<?php 

if(isset($_POST['submit'])){

    $row1 = $_POST['username'];
    $row1 = mysql_real_escape_string($row1);

    mysql_query("UPDATE members SET isMcount = isMcount + 1 WHERE username = '".$row1."' ") or die(mysql_error());
    $_SESSION['success'] = 'Page Updated';
    header('Location: '.DIRADMIN);
    exit();

}

?>
<form method="post">
<select name="username">
<?php 
$sql = mysql_query("SELECT username FROM members");
while ($row1 = mysql_fetch_array($sql)){
    echo "<option value=\"" . $row1['username'] . "\">" . $row1['username'] . "</option>";
}

?> 
</select>
<input type="submit" name="submit" value="Submit" class="button" />

</form>

A:

You have wrong HTML part. Try option below. "username" is field name for select and will be available on $_POST['username'] with a value of username for your user.
<form method="post">
<select name="username">
<?php 
$sql = mysql_query("SELECT username FROM members");
while ($row1 = mysql_fetch_array($sql)){
    echo "<option value=\"" . $row1['username'] . "\">" . $row1['username'] . "</option>";
}

?> 
</select>
<input type="submit" name="owner" value="submit"/>
</form>

And you can remove isMCount from $_POST in PHP as you don't need it.
And then you update query would be:
mysql_query("UPDATE members SET isMcount = isMcount + 1 WHERE username = '" . $row1 . "'");

