Php drop-down box

Php drop-down box If (! Isset ($ _ GLOBAL_NEWS_QIKAN_TYPES )){
$ _ GLOBAL_NEWS_QIKAN_TYPES = array ('1' => 'precat ',
'2' => 'management column ',
'3' => 'R & D? Technology ',
'4' => 'market Express ',
'5' => 'beebot home ',
'6' => 'recommendation? Sharing ',
'7' => 'travel? Life'
);
}



$ Global_news_type_inc = array ();
$ Global_news_type_inc ['1'] = 'industry News ';
$ Global_news_type_inc ['2'] = 'Journal ';
?>
The above are two arrays. when I select a journal, what is the drop-down box of the above array? Please give me some advice. use php.

Reply to discussion (solution)

Js controls. first, set the select box above to the display: none attribute. Then, when the second select box selects a journal, set it to display: block.

Agree with the upstairs statement, add onclick in select, call js function for tag attribute processing, display setting disply: block otherwise dispau: none

This cannot be solved with PHP. JS can process pages dynamically, but PHP cannot. JS is also very easy. it can be done with two or three sentences...
Positive solution of the upstairs method ~
They are all new users and are taught!

Agree with the upstairs statement, add onclick in select, call js function for tag attribute processing, display setting disply: block otherwise dispau: none

Search on the Internet, and there are many examples of JS multi-level linkage...