On selection of the first list box my page is not reloading
This value of cat is available now for our second drop down list box to use after the page reloads. Here to collect the value of cat from address bar we have to use like this.
Now value of $cat is available and it is a good idea to test the value of $cat by giving a print command to check the value. Now once the value of cat is available it should go to the second drop down box query. If you have doubt then print the second query to screen and see how it is constructed. It is always a good idea to print the MySQL error message to screen after the mysql_query() command.
I want to include this along with my other form field components.
If you are submitting the form with drop down list boxes to another page and using another form with other details to be filled then use hidden tags to keep the drop down selected values in second form.