Pset7 pass data to drop down bottom

Question

I'm now trying to make the sell button, and have a problem.
I try to do the query from data base just like index.php did.
And then I transfer the $rows results to sell_form.php(where show the button).
But it's clearly a error here, how can I fix this?

Here's the picture of the code and error page.
Sell.php
Sell_form.php
Sell.php(web)

Answer 1

The query returns what? An array. From Pic 1, $rows looks like this:

$rows[0]["symbol"] = "ATT";
$rows[1]["symbol"] = "MMM";
$rows[2]["symbol"] = "X";  

At the foreach in Pic 2, $stocks is an array of arrays, each $value is an array. Thus the echo provokes the "array to string conversion" error.