When you submit a form with a select input then it's the 'value' field that gets submitted, not the display text. Which means you cannot get the display text from your PHP code because it is not submitted to your PHP code.
Whatever value you need to have submitted to your PHP code needs to be the value of the value tag.
The dropdown field is getting generated dynamicly with java script and I have the value and the text according to the value in an array.
Is it possible to access this array with the php file? So I would have the value and the text...?