Hello, i am struggling here with a little problem. Actually i almost do the exact same things like here:

http://wiki.developerforce.com/index.php/Extended_Functionality_of_Visualforce_-_Part_2

but it not everything works.

 The problem:

I have an object with a field, Category__c, so every record has a category. I have a VF page where the categories are listed in a picklist and the records in a datatable. I want that it shows only the records with the category i have chosen.

What works:

I have rendered the picklist with this:

       public List<SelectOption> getCategories()
        {
          List<SelectOption> options = new List<SelectOption>();
               
           Schema.DescribeFieldResult fieldResult = obj__c.Category__c.getDescribe();
          
           List<Schema.PicklistEntry> ple = fieldResult.getPicklistValues();
                options.add(new SelectOption('All', 'All'));
           for( Schema.PicklistEntry f : ple)
              options.add(new SelectOption(f.getLabel(), f.getValue()));
           return options;
        }  

And the datatable works too.

Now i need the selected value in the picklist. I tried this(like in the link above):

    String category;
    public String getCategory() { return this.category; }
    public void setCategory(String s) { this.category = s; }

But when I do System.Debug, it says category is null, but i see that 'All' is selected.

The list looks like this:

        <apex:selectList value="{!category}" id="category" size="1" required="true">
          <apex:selectOptions value="{!Categories}"/>
          <apex:actionSupport event="onchange" rerender="dataTable"/>
        </apex:selectList>    

As you see i am facing 2 problems.

1. I don't get the selected Picklistvalue from the VF-Page

2. the "onchange" event doesn't work. Nothing happens when I change the Picklistvalue.