On my main homepage, I have 2 forms.

The first form only consist of a dropdown box.
When a user selects, New York and hits the "go" button, it will
redirect to mymainpage.com/newyork.php

Code HTML4Strict:
<form name="navList" onsubmit="return submitForm();">		
<b>Select your state</b></font><font face="Arial"><font size="2"> </font>
<select name="subMenu">
<option value="home"> </option>
<option value="Washington.php">	Washington DC	</option>
<option value="newyork.php">New York</option>
<option value="Alabama.php">	Alabama	</option>
<option value="Alaska.php">	Alaska	</option>
<option value="Arizona.php">	Arizona	</option>
<option value="Arkansas.php">	Arkansas	</option>
<option value="California.php">	California	</option>
</select><font size="2"> </font>
<input type="submit" value="Go"><font size="2"> </font>

then inside my newyork.php, there are some information about New York.
and some db stuff such as
PHP Code:
$result mysql_query("SELECT * FROM `table` WHERE `city_state` = 'New York' 

All that was created a month ago.
However, just recently, I decided to add in a function where user can select the category that they wish to see.

So, that is why I have also added another form,
and this form also consist of only a drop down box.

PHP Code:
<form method="POST" action="category.php"><b>Category</b>
//create a single array of options
$opts = array( 'Automobile''Apparel','Careers','Consumer goods','Education','Electronics','Food and Beverage','Furniture','General Business','Society');

//  Use here to create your form elements

echo '<select name="option">' PHP_EOL

foreach ( 
$opts as $key=>$val )
'<option value="'.$val '">' $val '</option>' PHP_EOL 

'</select>' PHP_EOL;

<input type="submit" name="submit" value="Go">

Both of the forms works perfectly on THEIR OWN!
They have their separate functions, and separate "submit" buttons.
They go to their own separate php pages.

But, I want to combine both of them into just 1 form, and 1 submit button.

This is so that the user can choose both drop down box value at once.
Example, the user can select "New york" AND "Apparel".
Result: It goes to mymainhomepage.com/newyork.php and shows all the post related to apparel.

How can I do this ?

Thanks a BILLION for your generous support and kind assistance.
May everyone here have a blessed week ahead!