select field question

[fife]

Hi.  I have two select fields one called category and the other sub category.  Both are in the format.

<select name="category" value="
							<?php $qGetCat = "SELECT * FROM club_category" ;
							$rGetCat = mysql_query($qGetCat);
							while ($Cat = mysql_fetch_assoc($rGetCat))
							{
							?>" />
                                <option value="<?php echo $Cat['categorys'];?>"><?php echo $Cat['categorys']; ?></option>
                                <?php } ?>
                                </select>

<select name="sub_category" value="
							<?php $qGetSubCat = "SELECT * FROM sub_categorys" ;
							$rGetSubCat = mysql_query($qGetSubCat);
							while ($SubCat = mysql_fetch_assoc($rGetSubCat))
							{
							?>" />
                                <option value="<?php echo $SubCat['sub_categorys'];?>"><?php echo $SubCat['sub_categorys']; ?></option>
                                <?php } ?>
                                </select>

 

 

Now I want to make it so that when a particular category is chosen for example self defence.  The sub category when clicked shows all the self defence stuff.  If watersports was chosen sub category would show things like swimming.  What do I need to look up to do this? At the minute there is no link the way I have coded these to fields.

 

In the database its self there is a;

 

category table with categoryID and category_name

 

sub category table with sub_cat_name and categoryID

 

I think this will work but I have never done this so its making my head hurt just thinking about it.  Does anyone have any advice, tuts or scripts to do this? 

 

Thank you

[BlueSkyIS]

2 options, both involving javascript:

 

1. add onchange event to first selection to submit the form and populate the 2nd select

or

2. add onchange event to first selection to use ajax to populate the 2nd select

[fife]

thank you  I will hunt these down now

 

[Pikachu2000]

FYI: the markup is not valid. <select> tags do not get a value= attribute, just a name= attribute. Only the <option> tags get a value= attribute.